part 1-1/2 × 13 mm.; proximal end narrower; on mid-anterior surface of

tarsometatarsus between Mm. extensor brevis digiti IV and extensor hallucis longus and mostly proximal to M. extensor brevis digiti III; tendinous distal part superficial to latter; fleshy belly ending immediately distal to proximal end of latter.

ORIGIN.--The origin is fleshy from a narrow elongate area on the mid-anterior surface of the tarsometatarsus between Mm. extensor brevis digiti IV and extensor hallucis longus, beginning at the distal end (bony) of the elongate accessory insertion of M. tibialis anticus. The distal part of the belly is free.

INSERTION.--The attachment is by a thin, wide (relative to belly) tendon to the superficial surface of M. extensor brevis digiti III.

INNERVATION.--Not found.

INDIVIDUAL VARIATION.--In P.p. 1L, the muscle is less well developed. The fleshy belly is 1 × 5 mm. It arises from the lateral edge of M. extensor hallucis longus. The extremely slender insertional tendon attaches as above.

=_M. Extensor Brevis Digiti IV_=, Figs. 19E, 20N

_T. pallidicinctus_

GENERAL DESCRIPTION AND RELATIONS.--Slender and tapering; on lateral part of anterior surface of tarsometatarsus; length of belly variable; middle of medial edge in contact with M. extensor hallucis longus.

ORIGIN.--The origin is fleshy from the lateral part of the anterior surface of the tarsometatarsus, including the anterior metatarsal groove.

INSERTION.--The long slender tendon enters the anterior aperture of the distal foramen, passes through the intertrochlear canal, emerges from the terminal foramen, and attaches to the medial surface of the proximal end of the first phalanx of digit IV.

INNERVATION.--The superficial peroneal branch of the peroneal nerve sends a twig into the proximal part of the muscle.

INDIVIDUAL VARIATION.--None of significance in any of the three species studied.

=_M. Lumbricalis_=, Fig. 19F

_T. pallidicinctus_

GENERAL DESCRIPTION AND RELATIONS.--Small, thin, and strap-shaped; on mid-posterior surface of distal end of tarsometatarsus deep to tendon of M. flexor digitorum longus; belly partly fleshy and partly elastic connective tissue.

ORIGIN.--The muscle arises from the deep (anterior) surface of the tendon of M. flexor digitorum longus a short distance proximal to the trifurcation of the latter.

INSERTION.--The muscle attaches to the proximal end of the subarticular cartilage ventral to the trochlea for digit III.

INNERVATION.--A long but extremely small twig arises from the paraperoneal branch of the tibial nerve a short distance distal to the hypotarsus and extends distally along the mid-posterior surface of the tarsometatarsus (parallel to a larger nonmuscular branch) and enters the deep surface distal to the middle. It was possible to follow this twig in only two legs; it was presumably destroyed in the course of dissection in the others.

INDIVIDUAL VARIATION.--In some cases, the "muscle" appears grossly to be entirely connective tissue, although a distinct entity.

_T. cupido_

INDIVIDUAL VARIATION.--In some cases, the "muscle" appears grossly to be entirely connective tissue. The innervation was found in only one leg, in which the twig arises more distally than in _T. pallidicinctus_.

_P. p. jamesi_

The innervation was not found.

=_M. Abductor Digiti IV_=, Fig. 19F

_T. pallidicinctus_

GENERAL DESCRIPTION AND RELATIONS.--Slender and elongate; on posterior surface of tarsometatarsus lateral to midline; in contact with M. flexor hallucis brevis in midline.

ORIGIN.--The origin is fleshy from the posterior surface of the tarsometatarsus lateral to the midline beginning near the proximal end (lateral to the hypotarsus) and ending at the level of the first metatarsal.

INSERTION.--The slender tendon, which begins along the lateral edge of the distal part of the belly, passes through a retinaculum on the posterolateral surface of the tarsometatarsus immediately above the outer trochlea and attaches to the lateral surface of the proximal end of the first phalanx of digit IV.

INNERVATION.--The paraperoneal branch of the tibial nerve gives one or two twigs to the proximal part of the muscle.

INDIVIDUAL VARIATION.--None of significance in any of the three species studied.

=_M. Flexor Hallucis Brevis_=, Fig. 19F

_T. pallidicinctus_

GENERAL DESCRIPTION AND RELATIONS.--Slender and elongate; on posterior surface of tarsometatarsus medial to midline; belly (except proximal end) adjacent (lateral) to posterior metatarsal crest; proximal end passing under latter (immediately distal to hypotarsus) and lying anteromedial to hypotarsus.

ORIGIN.--The origin is fleshy from the medial metatarsal depression and from the posterior surface of the tarsometatarsus between the midline and the posterior metatarsal crest beginning immediately below the hypotarsus and ending a short distance above the first metatarsal (sometimes more proximally).

INSERTION.--The slender tendon, which begins along the medial edge of the distal part of the belly, passes through the groove on the posterodistal surface of the first metatarsal and onto the proximal end of the ventral surface of the hallux; the tendon widens considerably and attaches by its edges to the ventral surface of the proximal end of the first phalanx, forming a short "tunnel" through which the tendon of M. flexor hallucis longus passes.

INNERVATION.--The paraperoneal branch of the tibial nerve sends one or two twigs into the proximal part of the muscle (but distal to the hypotarsus).

INDIVIDUAL VARIATION.--In two legs, the muscle arises in part from the distal end of the lateral calcaneal ridge. The individual variation is insignificant in _T. cupido_ and _P. p. jamesi_.

DISCUSSION AND CONCLUSIONS

_Analysis of Individual Variation_

Considerable individual variation occurs in both the muscles and the nerves of the leg of the three species studied. The amount of variation reported by a worker depends in large part on the degree of variation that he considers significant.

Individual variation in the muscles and in the nerves will be discussed separately; that of the muscles (excluding innervation) will be considered first.

Muscles

Considering the number, rather than degree, of variations, the most variable muscles are: Mm. flexor digitorum longus, obturator, caudofemoralis, and extensor hallucis longus. The first-mentioned muscle exhibits 14 different variations in the specimens studied. Mm. vastus lateralis, flexor perforans et perforatus digiti II, and piriformis also showed a considerable number of variations. The following muscles did not exhibit any variations considered significant in this study: Mm. vastus medialis, femoritibialis internus, flexor perforatus digiti III, extensor brevis digiti III, and abductor digiti IV.

Muscles showing a great _degree_ of individual variation included the following: M. extensor proprius digiti III was present in two legs of _Pedioecetes_ but absent in the other legs studied. A fleshy muscle slip connected M. caudofemoralis pars caudifemoralis with the tendinous raphe between Mm. flexor cruris lateralis and femorocruralis in two legs, whereas in others this connection was tendinous or even absent altogether. M. caudofemoralis pars caudifemoralis had a tendinous area within the belly in only three legs. A vinculum connected the insertional tendons of Mm. flexor perforans et perforatus digiti II and flexor perforatus digiti II in only one leg. The fleshy belly of M. iliotrochantericus medius was completely split into two parts in one leg. M. flexor cruris lateralis had an accessory slip arising from the caudal musculature in one leg.

Certain individual variations reported in the accounts of the muscles formed a graduated series, as far as degree is concerned, from the typical to the extreme condition. Therefore it was difficult or impossible in some cases to state whether or not certain specimens exhibited such a variation. Elimination of the doubtful instances of variation leaves a total of 50 different variations (excluding variations between species) which can be attributed to a definite number of specimens. The remainder of the discussion of individual variation in the muscles concerns these 50 variations. See table 3.

The typical condition of any structure is considered to be the condition of that structure in the majority of the legs studied. Some conditions considered as typical in the present study might not be so considered if a larger number of specimens had been studied. If exactly half of the legs of one species shows a particular condition of a structure, the condition typical for this species is considered (for purposes of the following discussion) to be that found in the majority of the legs of the other species.

In all instances except two (of 50) the typical condition of the muscles in _T. pallidicinctus_ was also the typical condition in _T. cupido_. The majority of the legs in _T. cupido_ had an additional dorsal slip on the tendon of M. flexor digitorum longus in digits II and III. In all instances except seven the typical condition in _T. pallidicinctus_ was also the typical condition in _Pedioecetes_. In these seven instances a variation in the former was the typical condition in the latter. These were: an additional dorsal slip on the tendon of M. flexor digitorum longus in each of three digits, a vinculum between the latter and M. flexor perforatus digiti IV, a partly fleshy insertion of M. flexor cruris medialis, an unossified lateral branch of the insertional tendon of M. extensor digitorum longus, and an independent insertion of the distalmost fibers of the distal head of M. extensor hallucis longus. For all characters except the number of the dorsal slips on the tendon of M. flexor digitorum longus in digits II and III, the typical condition in _T. pallidicinctus_ was also the typical condition for all species considered together. To facilitate comparison, in the following discussion all of the above-mentioned characters are considered in all species as variants from the typical condition.

Certain legs showed a greater number of variations from the typical condition than did others. The majority of legs showed from four to seven variations in the muscles of the leg. The extremes were P.p. 1L, which showed 11, and T.c.p. 2L, which exhibited only one variation.

Twenty-three of the 50 variations were found in only one leg (out of 23). It would be expected that if additional specimens were studied, more kinds of variations would be found. Nine variations were found in only two legs, five in three legs, five in four legs, and four in five legs. One variation was found in nine legs, one in ten legs, and two in 12 legs; the last four variations were in the number of dorsal slips of the insertional tendon of M. flexor digitorum longus in digits II, III, and IV and in the ossification of the insertional tendon of M. extensor digitorum longus.

Five of the variations were found only in specimens in which only one leg was dissected. Considering only those eight specimens in which both legs were dissected, five of the 45 variations were found in both legs of each specimen exhibiting the variation; 28 variations were found in only one leg of each specimen exhibiting the variation; 12 variations were found in both legs of some specimens but in only one leg of other specimens. Of the six muscle features showing the greatest degree of individual variation (described previously), only two (both pertaining to M. caudofemoralis) were found in both legs of the specimens exhibiting the variation.

For one leg (the one showing the most variations) of each specimen of which both legs were studied, the number of variations that this leg had in common with every other leg (of all species) was determined. Then the number of variations in common between the two legs of one individual was compared with the number of variations in common between one leg of this individual and each leg of every other individual. See table 4. One leg of six of the eight specimens showed at least as many variations in common with a leg of another individual as with the other leg of the same individual. The two exceptions were T.p. 2R and T.c.a. 1R. Thus for most specimens there was as much variation in the muscles between the right and left legs of one individual as there was between individuals.

Of the 50 muscle variations seven were found only in _T. pallidicinctus_ (eight legs), 16 were found only in _T. cupido_ (nine legs), and ten were found only in _Pedioecetes_ (six legs). Two were found in both species of _Tympanuchus_ (but not in _Pedioecetes_). Fifteen were found in both _Tympanuchus_ and _Pedioecetes_; of these, five were found in all three species studied, eight were shared by _T. pallidicinctus_ and _Pedioecetes_, and two occurred in _T. cupido_ and _Pedioecetes_.

Nerves

The lumbosacral plexus, femoral nerve, sciatic nerve, and tibial nerve all showed numerous individual variations. The peroneal nerve, however, was relatively constant. Variations in the obturator nerve were considered to be insignificant. See table 5.

In all instances except one (of 40) the typical condition in _T. pallidicinctus_ was also the typical condition in _T. cupido_. In most of the legs of the latter the nerve to M. flexor cruris lateralis did not perforate M. caudofemoralis. In all instances except four the typical condition in _T. pallidicinctus_ was also the typical condition in _Pedioecetes_. These exceptions were: prefixation of the lumbosacral plexus, six roots of the sciatic nerve, femoral nerve formed mainly from S2 to S4 and two twigs to M. flexor ischiofemoralis. In all instances the typical condition in _T. pallidicinctus_ was also the typical condition for all species considered together.

Certain legs showed a greater number of variations from the typical condition of the nerves than did others. The greatest number of variations was shown by P.p. 3L, which had 12. T.p. 1R and T.c.p. 1L both showed only one.

All six variations in the lumbosacral plexus were found on both sides of each specimen exhibiting the variation. In marked contrast to the other nerves, there was no significant variation in the lumbosacral plexus between the right and left sides of one individual. (This might not always be true, however, if a larger number of specimens were studied.) Of the variations in the lumbosacral plexus, one was found in only one specimen (of 15), one was found in three specimens, one in four specimens, two in six specimens, and one in seven specimens. Of the 34 variations found in the other nerves, 14 were found in only one leg (of 23), six occurred in two legs, four in three legs, three in four legs, three in five legs, two in six legs, one in seven legs, and one in nine legs.

Four of the variations were found only in specimens in which only one leg was dissected. Considering only those eight specimens in which both legs were dissected, and excluding the lumbosacral plexus, ten of the 30 variations were found in both legs of each specimen exhibiting the variation; 16 variations were found in only one leg of each specimen exhibiting the variation; four variations were found in both legs of some specimens but in only one leg of other specimens.

The number of variations in common between the two legs of one individual was compared with the number between individuals in the same manner as for the muscles; the lumbosacral plexus was excluded from consideration. See table 6. One leg of six of the eight specimens showed at least as many variations in common with a leg of another individual as with the other leg of the same individual. The two exceptions were T.p. 2L and T.p. 3R. Thus for most specimens there was as much variation in the nerves other than the lumbosacral plexus between the right and left legs of one individual as there was between individuals.

Of the 40 nerve variations (including the lumbosacral plexus) 11 were found only in _T. pallidicinctus_, seven were found only in _T. cupido_, and seven were found only in _Pedioecetes_. Four were found in both species of _Tympanuchus_ (but not in _Pedioecetes_). Eleven were found in both _Tympanuchus_ and _Pedioecetes_; of these, four were found in all three species, three were shared by _T. pallidicinctus_ and _Pedioecetes_ and four occurred in _T. cupido_ and _Pedioecetes_.

The average number of variations per leg in both muscles and nerves was 11 in _T. pallidicinctus_, nine in _T. cupido_, and 16 in _Pedioecetes_. The high number in the last is in part the result of these being variations from the typical condition of _T. pallidicinctus_ (rather than from _Pedioecetes_).

_Analysis of Variation Between Species_

No constant differences in the muscles or nerves was found between _T. cupido pinnatus_ and _T. cupido attwateri_. Only one constant difference was found between _T. cupido_ and _T. pallidicinctus_: a thicker fleshy origin of M. extensor iliotibialis lateralis in _T. cupido_ (associated with a thicker edge of the lateral iliac process).

Although no constant differences in the nerves were found between _Pedioecetes_ and _Tympanuchus_ (both species), 17 constant differences in the muscles were found between these two genera. Seven of these differences pertain to features of a single muscle--M. flexor cruris medialis. Compared with the condition in _Tympanuchus_, M. flexor cruris medialis in _Pedioecetes_ has a wider origin, a partly fleshy (instead of entirely tendinous) origin, a more pronounced curvature of the line of origin, a wider insertion, an insertion posterior (rather than anterior) to the medial collateral ligament, an insertion that attaches in part to the articular capsule, and a shorter tendon of insertion (resulting in the fusion of the common insertional tendon of Mm. flexor cruris lateralis and femorocruralis with the fleshy belly rather than with the insertional tendon). Other differences include the following. A more extensive posteroproximal aponeurosis of M. extensor iliotibialis lateralis in _Pedioecetes_ (resulting in a narrower fleshy origin); a more nearly straight line of origin of this muscle (associated with a less pronounced lateral iliac process); a thinner fleshy origin of this muscle (associated with a thinner edge of the lateral iliac process); a wider M. flexor cruris lateralis that is fleshy up to the origin from the vertebrae; a wider fleshy origin of M. iliacus; the origin of M. caudofemoralis pars iliofemoralis not reaching the ventral edge of the ischium; a narrower origin of M. adductor superficialis; a wider M. femorocruralis; and a shorter belly of M. extensor digitorum longus. Some additional differences between these two genera, which are slight in degree, are given in the accounts of the muscles. If additional specimens were studied, some of the differences listed above possibly would prove to be subject to individual variation and so could not properly be listed as constant differences between the two genera.

The picture of the differences between _Tympanuchus_ and _Pedioecetes_ that the present study presents is radically different from that presented by the study of Hudson, _et al._ (1959). These authors reported the following differences between these two genera. (I am using my terminology.) The origin of M. piriformis is narrower in _Pedioecetes_ and is more posteriorly situated; the belly of M. extensor iliotibialis anticus is broader in _Pedioecetes_; the belly of M. tibialis anticus is longer; the belly of M. peroneus brevis is shorter; the insertional tendon of the anterolateral head of M. flexor perforatus digiti III is shorter; the belly of M. flexor digitorum longus is shorter; only two (rather than three) of the branches of M. extensor digitorum longus on the tarsometatarsus are ossified; the posterior metatarsal crest is shorter; M. flexor perforans et perforatus digiti II has two heads in _Pedioecetes_ but only one in _Tympanuchus_; the roof over the hypotarsal canal enclosing the tendon of M. flexor digitorum longus is bony in _Pedioecetes_ but fibrous in _Tympanuchus_; M. flexor cruris lateralis is wider in _Pedioecetes_; and the origin of M. femorocruralis is wider. I paid particular attention in my study to these 13 features given by Hudson, _et al._; of these the only differences that I found to be constant were the last two. The apparent reason for this great discrepancy is the small number of legs of _Tympanuchus_ studied by Hudson, _et al._ They studied eight legs of _Pedioecetes_ but only two legs of _Tympanuchus_. This emphasizes the danger of making comparisons based on a very small number of specimens (a criticism which may prove to apply to the present study as well). The reason why Hudson, _et al._ did not report most of the differences found by me is not so apparent. Either the specimens studied by the former workers showed a greater variation in these characters than did my specimens or else those workers overlooked the differences. Probably both factors are involved. It remains to be determined how many specimens need to be studied in order to obtain a fairly accurate picture of variation.

_Comparison with Other Studies of Innervation_

I accept the following concept of muscle-nerve relationship. All muscles of the pelvic limb of birds have developed phylogenetically from either the dorsal extensor muscle mass or the ventral flexor muscle mass. The former was (at least originally) supplied by only the femoral and peroneal nerves ("dorsal" nerves), the latter by only the obturator and tibial nerves ("ventral" nerves). The best guide for determining which muscles are phylogenetically dorsal and which are ventral seems to be their embryogeny (as shown in the studies of Romer, 1927, and Wortham, 1948). In the phylogenetic changes undergone by the muscles under consideration, the innervation may have changed in some instances, although this is less likely to occur than changes in the attachment or function of the muscles. If a change in innervation has occurred, it would be more likely to be a change from one dorsal nerve to the other or from one ventral nerve to the other rather than from a dorsal nerve to a ventral one or _vice versa_.

Thus, in my opinion, a report of a dorsal muscle supplied by a ventral nerve, or _vice versa_, should be viewed with suspicion until it is verified. I suspect that many previous workers have ignored this concept of muscle-nerve relationship, or else do not accept it, since they report, without comment, dorsal muscles (as determined embryologically) innervated by ventral nerves, or _vice versa_. Owing to the intimate association between the proximal parts of the tibial and peroneal nerves, the true relationship may be difficult to determine. I suspect that this relationship has been misinterpreted by a number of workers. I found in _Tympanuchus_ and _Pedioecetes_ a branch of the tibial nerve that is closely associated with, and distributed with, the peroneal nerve and has been mistakenly considered a part of the peroneal nerve by some workers. In the study here reported on, I have found no definite exceptions to the expected innervation. The only possible exception is an extra branch, which could not be traced to its origin, supplying M. extensor iliofibularis in one leg. Thus my study of innervation agrees with the embryological determination of the (phylogenetic) dorsal and ventral muscles and lends strong support to the above-stated concept of muscle-nerve relationship.

I have compared my findings on the nerves with those of other workers, who have studied the nerves with a varying degree of thoroughness. The important differences in innervation between these studies and the present one are discussed below.

In neither of Gadow's works did he distinguish tibial and peroneal components in the thigh. In his later work (1891), covering a wide variety of birds, he found that M. piriformis sometimes has a femoral innervation in addition to the constant sciatic one and that M. gluteus profundus may or may not have a sciatic supply in addition to the femoral one. A comparison of Gadow's terminology of the sciatic nerve branches in the shank and foot (in both works) with mine shows that his branch I represents my peroneal nerve plus my paraperoneal branch of the tibial nerve (Ic); his branch II represents my medial division of the tibial nerve; and his branch III represents my posterior (IIIa) and lateral (IIIb) divisions of the tibial nerve.

Gadow's study (1880) on the ratites included _Struthio_, _Rhea_, and _Casuarius_. Only in _Casuarius_ did Gadow find a branch (IIe) of the sciatic nerve supplying Mm. lumbricalis, adductor digiti II, and abductor digiti II. The two former muscles are typically supplied (as in _Rhea_) by the paraperoneal branch of the tibial nerve; Gadow's branch IIe presumably represents a segregated branch of this nerve. More surprising is his finding that M. abductor digiti II is innervated in _Casuarius_ by both the deep peroneal nerve and branch IIe and in _Rhea_ by branch Ic (paraperoneal branch of tibial nerve). The deep peroneal innervation is typical. Also unexpected is his finding that the posterior division of the femoral nerve gives minute twigs into M. gastrocnemius pars interna in _Struthio_ and _Casuarius_. Since the other terminal branches of this nerve in these birds are nonmuscular, since this muscle is chiefly supplied by other nerves, and since the innervation from the femoral nerve is apparently atypical for most birds, the possibility should be considered that the femoral twigs are sensory rather than motor.

Sudilovskaya (1931), studying _Struthio_, _Rhea_, and _Dromaeus_ (_Dromiceius_), used the same terminology as Gadow except that he designates as branch III Gadow's branch Ic. Sudilovskaya's discussion of the main branches of the sciatic nerve is confusing. He states that in _Struthio_, branches I, II, and III all pass through the tendinous guide loop for M. extensor iliofibularis; this is hard to believe. As near as I can determine, he has mistakenly given the same designation (branch III) to two separate branches (Gadow's Ic and III). There is no problem, however, in determining to which of these two branches he is referring when he is describing the innervation of a particular muscle, since one supplies only muscles of the shank and the other only intrinsic foot muscles. Sudilovskaya found M. abductor digiti II to be innervated by branch III (Ic of Gadow); thus the innervation of this muscle corresponds to that found in _Rhea_ by Gadow. Although M. adductor digiti II had the expected innervation from branch III (paraperoneal branch of tibial nerve) in _Dromaeus_, that muscle was found to be supplied by branch II in _Rhea_. (Gadow, on the other hand, reports a typical innervation for this muscle in _Rhea_.) Sudilovskaya found M. peroneus brevis to be supplied by the deep peroneal branch (in contrast to the superficial peroneal supply that I found in _Tympanuchus_ and _Pedioecetes_). He found M. gastrocnemius pars interna to be supplied in _Struthio_ by twigs of the femoral nerve in addition to its typical innervation from branch II of the sciatic nerve; this agrees with Gadow's findings in the same genus. Sudilovskaya reports that M. gastrocnemius pars externa was innervated by branches II and III in _Struthio_ and _Rhea_ and by branches I and III in _Dromaeus_. (Gadow found only the typical innervation--branch III.)

In the Whooping Crane, Fisher and Goodman (1955) found a peroneal, rather than a femoral, nerve supply for pars postica of M. vastus lateralis. They also report a peroneal nerve supply for M. flexor ischiofemoralis (in contrast to the usual tibial nerve supply) and for M. adductor superficialis (in addition to the usual supply from the obturator nerve). The innervation was not given for the intrinsic foot musculature.

Fisher (1946), studying vultures, reports the following: tibial branches, in addition to the main sciatic branch, supplying M. extensor iliofibularis (typically supplied by the peroneal nerve); an obturator supply, in addition to the usual tibial supply, to M. flexor cruris medialis; a tibial supply, in addition to the typical obturator supply, to M. obturator pars postica; a possible obturator supply, in addition to the typical femoral supply, to M. ambiens; a possible peroneal supply, in addition to the typical tibial supply, to M. flexor digitorum longus; and a peroneal supply to Mm. abductor digiti IV, flexor hallucis brevis, and adductor digiti II (which are typically supplied by the paraperoneal branch of the tibial nerve). Fisher's postfibular branch of the peroneal nerve, which supplies the latter three muscles, apparently represents the paraperoneal branch of the tibial nerve.

Carlsson (1884) did not find a femoral nerve supply for M. gluteus profundus. He found an obturator supply, in addition to the usual sciatic supply, to M. flexor ischiofemoralis in _Eudyptes chrysolopha_ and _Mergulus alle_ but not in the other two forms studied. He reported a peroneal supply, rather than the expected tibial (paraperoneal) supply, to Mm. abductor digiti IV and adductor digiti IV.

DeMan (1873) found a twig of the obturator nerve supplying M. flexor ischiofemoralis, in addition to the typical innervation, in _Corvus monedula_, but not in the few other forms studied. He did not distinguish tibial and peroneal components in the thigh.

Wilcox (1948), studying a loon, did not find any peroneal supply to M. extensor iliotibialis lateralis or to M. gluteus profundus. He found a femoral, rather than a peroneal, supply to M. piriformis. He found an obturator, instead of a tibial, supply to M. flexor ischiofemoralis. (In some of my specimens I found a tiny blood vessel, appearing much like a nerve, emerging from the obturator foramen and entering M. flexor ischiofemoralis.) Wilcox reports an innervation of M. caudofemoralis pars caudifemoralis from the pudendal plexus, in addition to the usual sciatic one. Wilcox did not distinguish tibial and peroneal components in the thigh. In the shank and foot he misidentified the peroneal nerve as the tibial nerve and therefore gave erroneous innervations for all the muscles supplied by this nerve, except for M. adductor digiti IV, which actually should be supplied by the tibial nerve.

Howell (1938) studied only the hip and thigh musculature of the chicken. He overlooked the femoral nerve supply for M. gluteus profundus.

Romer (1927) studied only the hip and thigh muscles of the chick. He did not distinguish tibial and peroneal components in the thigh. He did not mention any sciatic supply for M. gluteus profundus.

Appleton (1928), studied (in various birds) only those muscles of the hip and thigh that are innervated by the tibial and peroneal nerves. He terms the former "ischiadicus ventralis" and the latter "ischiadicus dorsalis." His findings did not differ from mine.

Many differences in the innervation of specific muscles are reported in the literature, even in the same species (by different workers). Some of these differences may be real; others are probably misinterpretations. Consequently more work needs to be done before a complete understanding can be obtained of the innervation of the leg muscles of birds. Especially needed are studies of the tibial-peroneal nerve relationship, perhaps approached by a method other than gross dissection.

SUMMARY

The muscles and nerves were dissected in eight legs of the Lesser Prairie Chicken (_Tympanuchus pallidicinctus_), six legs of the Greater Prairie Chicken (_T. cupido pinnatus_), three legs of Attwater's Prairie Chicken (_T. c. attwateri_), and six legs of the Sharp-tailed Grouse (_Pedioecetes phasianellus jamesi_) for the purpose of obtaining information on individual variation as well as variation between these closely related species. Relatively little information is available regarding the nerves of the leg of birds and little is known about individual variation and variation between closely related forms in the muscles of the leg of birds.

All osteological terms used in the present paper are defined and those of the pelvis are illustrated. New terms were coined for some structures for which no names could be found in the literature. Terms were also coined for the major divisions of the femoral and sciatic nerves. With three exceptions, my muscle terminology follows that of Fisher (1946) and Fisher and Goodman (1955). Their term femoritibialis externus is not used here; the muscle so named is considered to be a part of M. vastus lateralis. Fisher's accessory head of M. flexor cruris lateralis is considered to be a distinct muscle--M. femorocruralis. Usage of the term obturator internus is avoided because the muscle so named is considered not to be homologous with the mammalian muscle of the same name; the entire obturator complex is called M. obturator, and is subdivided into four parts.

The typical (most common) condition of the nerves and muscles in _Tympanuchus pallidicinctus_ is described in detail. Variations from this condition among the other birds studied are then described. All muscles of one leg of _T. pallidicinctus_ are illustrated. Several variations in the muscles are also illustrated. The lumbosacral plexus and nerves of the leg in several specimens that show variations are illustrated.

Considerable individual variation was found in both the muscles and the nerves of the leg of the species studied. Certain muscles were more variable than others. Mm. flexor digitorum longus, obturator, caudofemoralis, and extensor hallucis longus showed the greatest number of variations. Mm. vastus medialis, femoritibialis internus, flexor perforatus digiti III, extensor brevis digiti III, and abductor digiti IV did not exhibit any variations considered significant. Certain legs showed a greater number of variations from the typical condition than did others.

Although most of the variations were minor, some were major. M. extensor proprius digiti III was present in two legs of _Pedioecetes_ but absent in the other legs studied. A fleshy muscle slip connected M. caudofemoralis pars caudifemoralis with the tendinous raphe between Mm. flexor cruris lateralis and femorocruralis in two legs, whereas in others this connection was tendinous or even absent altogether. M. flexor cruris lateralis had an accessory slip arising from the caudal musculature in one leg. A vinculum connected the insertional tendons of Mm. flexor perforans et perforatus digiti II and flexor perforatus digiti II in one leg.

In most specimens there was as much variation between the muscles of the right and left legs of one individual as there was between individuals. The same was true for the nerves, except for the lumbosacral plexus, in which there was no significant variation between the right and left sides of any individual. The peroneal and obturator nerves varied less than the other nerves.

No constant differences in the muscles or nerves was found between _T. cupido pinnatus_ and _T. c. attwateri_. One constant difference was found between _T. cupido_ and _T. pallidicinctus_: the fleshy origin of M. extensor iliotibialis lateralis in _T. cupido_ was thicker (associated with a thicker edge of the lateral iliac process).

Although no constant differences in the nerves were found between _Pedioecetes_ and _Tympanuchus_ (both species), 17 constant differences in the muscles were found between these two genera. Study of additional specimens possibly would show enough individual variation in some of these differences to reduce the number of constant differences to fewer than 17. Seven of these differences pertain to features of a single muscle--M. flexor cruris medialis. Some of the other differences are associated with the thinner and much less pronounced lateral iliac process in _Pedioecetes_. The picture of the differences between _Tympanuchus_ and _Pedioecetes_ that this study presents is radically different from that presented by the study of Hudson, _et al._ (1959).

The important differences in innervation between previous studies and the present one are discussed.

All of the muscles under consideration have been grouped as either dorsal or ventral muscles, according to their embryonic origin, as described by Romer (1927) and Wortham (1948). This grouping probably represents accurately the phylogenetic origin of these muscles. The dorsal muscles probably were originally supplied by dorsal nerves--the femoral and peroneal--and the ventral muscles probably were originally supplied by ventral nerves--the obturator and tibial. This primitive muscle-nerve relationship has been relatively constant.

Several previous workers have reported some dorsal muscles supplied by ventral nerves and _vice versa_. Those findings should be viewed with suspicion until verified, because the proximal parts of the tibial and peroneal nerves are intimately associated and their relationship is easily misinterpreted. I found a branch of the tibial nerve that is closely associated with, and distributed with, the peroneal nerve. That branch of the tibial nerve has been mistakenly considered a part of the peroneal nerve by some workers. My study revealed no definite exceptions to the expected innervation.

TABLE 1. SYNONYMY OF THE MUSCLES OF THE LEG OF BIRDS

===============+===============+============+==============+============== | | Howell | Fisher & | Gadow (1891) | Hudson (1937) | (1938) |Goodman (1955)| Holmes ---------------+---------------+------------+--------------+-------------- ilio-tibialis |ilio-tibialis |extensor |extensor |extensor | | iliotibia- | ilio-tibia- | iliotibialis | | lis latera-| lis | lateralis | | lis | lateralis | ---------------+---------------+------------+--------------+-------------- ilio-tibialis |sartorius |extensor |extensor |extensor internus s. | |iliotibialis| ilio-tibia- | iliotibialis sartorius | |anterior | lis anterior| anticus ---------------+---------------+------------+--------------+-------------- ambiens |ambiens |ambiens |ambiens |ambiens ---------------+---------------+------------+--------------+-------------- femori-tibialis| | |femoritibialis|vastus externus | | | externus | lateralis | | | |(a) pars | | | | postica ---------------+ | +--------------+ {|femori-tibialis|vastus |vastus |(b) pars femori- {| externus | lateralis | lateralis | lateralis tibialis {+---------------+------------+--------------+-------------- medius {|femori-tibialis|} {|vastus |vastus {| medius |} {| medialis | medialis ---------------+---------------+}vastus {+--------------+-------------- femori-tibialis|femori-tibialis|} medialis{|femoritibialis|femoritibialis internus | internus |} {| internus | internus ---------------+---------------+------------+--------------+-------------- ilio-fibularis |biceps femoris |extensor |extensor |extensor | | iliofibu- | ilio- | ilio- | | laris | fibularis | fibularis ---------------+---------------+------------+--------------+-------------- ilio-femoralis |glutaeus medius|piriformis |piriformis |piriformis externus | et minimus | | | ---------------+---------------+------------+--------------+-------------- ilio-trochante-|ilio-trochante-|gluteus |gluteus |gluteus ricus | ricus | profundus | profundus | profundus posterior | posterior | | | ---------------+---------------+------------+--------------+-------------- ilio-trochante-|ilio-trochante-|iliacus |iliacus |iliacus ricus | ricus | | | anterior | anterior | | | ---------------+---------------+------------+--------------+-------------- ilio-trochante-|ilio-trochante-| |ilio-trochan- |iliotrochante- ricus medius | ricus medius | | tericus | ricus medius | | | medius | ---------------+---------------+------------+--------------+-------------- ilio-trochante-|iliacus |psoas |psoas |psoas ricus | | | | internus | | | | ---------------+---------------+------------+--------------+-------------- caud-ilio- |semitendinosus |flexor |flexor cruris |flexor cruris flexorius | | cruris | lateralis | lateralis | | lateralis |(a) main head | ---------------+---------------+------------+ +-------------- accessorius |accessorius |femorocru- |(b) accessory |femorocruralis semitendinosi| semitendinosi| ralis | heads | ---------------+---------------+------------+--------------+-------------- ischio- |semimembranosus|flexor |flexor cruris |flexor cruris flexorius | | cruris | medialis | medialis | | medialis | | ---------------+---------------+------------+--------------+-------------- caud-ilio- |piriformis | |caudofemoralis|caudofemoralis femoralis | | | | (a) pars |(a) pars |caudofemo- |(a) pars |(a) pars caudi- | caudi- |ralis | caudi- | caudifemo- femoralis | femoralis | | femoralis | ralis | +------------+ | (b) pars ilio- |(b) pars ilio- |flexor ilio-|(b) pars ilio-|(b) pars femoralis | femoralis | femoralis | femoralis | iliofemo- | | | | ralis ---------------+---------------+------------+--------------+-------------- ischio- |ischio- |flexor |flexor ischio-|flexor femoralis | femoralis | ischiofe- | femoralis | ischiofemo- | | moralis | | ralis ---------------+---------------+------------+--------------+-------------- {|adductor longus|adductor |adductor |adductor {| et brevis | superfi- | superfici- | superficialis {|(a) pars | cialis | alis | pub-ischio- {| anterior | | | femoralis {| +------------+--------------+-------------- {|(b) pars |adductor |adductor |adductor {| posterior | profundus | profundus | profundus ---------------+---------------+------------+--------------+-------------- obturator |obturator |} {|obturator |} | internus |} {| internus |} ---------------+---------------+} obturator{+--------------+} obturator accessorii M. |obturator |} {|obturator |} obturatoris | externus |} {| externus |} ---------------+---------------+------------+--------------+-------------- gastrocnemius |gastrocnemius | |gastrocnemius |gastrocnemius ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor perfo- |flexor perfo- perforans et | perforans et | | rans et per-| rans et per- perforatus | perforatus | | foratus | foratus digiti II | digiti II | | digiti II | digiti II ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor perfo- |flexor perfo- perforans et | perforans et | | rans et per-| rans et per- perforatus | perforatus | | foratus | foratus digiti III | digiti III | | digiti III | digiti III ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor |flexor perfo- perforatus | perforatus | | perforatus | ratus digiti digiti IV | digiti IV | | digiti IV | IV ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor |flexor perfo- perforatus | perforatus | | perforatus | ratus digiti III | digiti III | | digiti III | digiti III ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor |flexor perfo- perforatus | perforatus | | perforatus | ratus digiti digiti II | digiti II | | digiti II | II ---------------+---------------+------------+--------------+-------------- flexor hallucis|flexor hallucis| |flexor hallu- |flexor hallu- longus | longus | | cis longus | cis longus ---------------+---------------+------------+--------------+-------------- plantaris |plantaris | |plantaris |plantaris ---------------+---------------+------------+--------------+-------------- flexor |flexor | |flexor digi- |flexor digito- profundus | digitorum | | torum longus| rum longus s. perforans | longus | | | ---------------+---------------+------------+--------------+-------------- popliteus |popliteus | |popliteus |popliteus ---------------+---------------+------------+--------------+-------------- peroneus |peronaeus | |peroneus |peroneus superficialis| longus | | longus | longus ---------------+---------------+------------+--------------+-------------- tibialis |tibialis | |tibialis |tibialis anticus | anterior | | anterior | anticus ---------------+---------------+------------+--------------+-------------- extensor |extensor | |extensor |extensor digitorum | digitorum | | digitorum | digitorum communis | longus | | longus | longus ---------------+---------------+------------+--------------+-------------- peroneus |peronaeus | |peroneus |peroneus profundus | brevis | | brevis | brevis ---------------+---------------+------------+--------------+-------------- extensor |extensor | |extensor |extensor hallucis | hallucis | | hallucis | hallucis brevis | longus | | longus | longus ---------------+---------------+------------+--------------+-------------- abductor |abductor | |abductor |abductor digiti II | digiti II | | digiti II | digiti II ---------------+---------------+------------+--------------+-------------- extensor brevis|} {| |extensor |extensor bre- digiti III |} extensor {| | brevis | vis digiti |} {| | digiti III | III ---------------+} proprius {+------------+--------------+-------------- extensor |} digiti {| |extensor |extensor proprius |} III {| | proprius | proprius digiti III |} {| | digiti III | digiti III ---------------+---------------+------------+--------------+-------------- extensor brevis|extensor brevis| |extensor |extensor bre- digiti IV | digiti IV | | brevis | vis digiti | | | digiti IV | IV ---------------+---------------+------------+--------------+-------------- flexor brevis |lumbricalis | | |lumbricalis digiti III | | | | ---------------+---------------+------------+--------------+-------------- abductor |abductor | |abductor |abductor digiti IV | digiti IV | | digiti IV | digiti IV ---------------+---------------+------------+--------------+-------------- flexor hallucis|flexor hallucis| |flexor |flexor hallu- brevis | brevis | | hallucis | cis brevis | | | brevis | ---------------+---------------+------------+--------------+-------------- adductor |adductor | |adductor | digiti II | digiti II | | digiti II | ---------------+---------------+------------+--------------+-------------- adductor |adductor | | | digiti IV | digiti IV | | | ---------------+---------------+------------+--------------+--------------

TABLE 2. RELATIVE SIZES (IN PERCENTAGES) OF SOME MUSCLES IN TYMPANUCHUS AND PEDIOECETES

===========================+=======================+====================== | _Tympanuchus_ | _Pedioecetes_ Muscle +-----+---------+-------+------+--------+------ | Ave.| Range | No.[1]| Ave. | Range |No.[1] ---------------------------+-----+---------+-------+------+--------+------ Iliacus: width of fleshy | | | | | | origin (divided by length| | | | | | of ilium) | .10 | .08-.11 | 13 | .19 | .17-.19| 6 ---------------------------+-----+---------+-------+------+--------+------ Flexor cruris lateralis: | | | | | | maximum width of exposed | | | | | | part (divided by length | | | | | | of ilium) | .22 | .19-.27 | 13 | .31 | .27-.36| 6 ---------------------------+-----+---------+-------+------+--------+------ Flexor cruris medialis: | | | | | | width of origin (divided | | | | | | by length of ilium) | .11 | .08-.16 | 13 | .22 | .19-.23| 6 ---------------------------+-----+---------+-------+------+--------+------ Flexor cruris medialis: | | | | | | width of insertion | | | | | | (divided by length of | | | | | | tibiotarsus) | .09 | .08-.13 | 13 | .17 | .15-.17| 4 ---------------------------+-----+---------+-------+------+--------+------ Adductor superficialis: | | | | | | width of origin (divided | | | | | | by length of ilium) | .20 | .17-.23 | 13 | .13 | .10-.16| 5 ---------------------------+-----+---------+-------+------+--------+------ Femorocruralis: distance of| | | | | | proximal end of origin | | | | | | from proximal end of | | | | | | femur (divided by length | | | | | | of femur) | .59 | .55-.63 | 13 | .40 | .38-.43| 6 ---------------------------+-----+---------+-------+------+--------+------ Extensor digitorum longus: | | | | | | length of fleshy belly | | | | | | (divided by length of | | | | | | tibiotarsus) | .73 | .64-.83 | 13 | .59 | .50-.62| 4 ---------------------------+-----+---------+-------+------+--------+------

FOOTNOTES:

[Footnote 1: No. = number of legs.]

TABLE 3. OCCURRENCE OF INDIVIDUAL VARIATIONS IN MUSCLES

===========================+===============+===========+======+=========== | T.p. | T.c.p. |T.c.a.| P.p. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+- |1|1|2|2|3|3|4|5|1|1|2|2|3|4|1|1|2 |1|1|2|3|3|4 |L|R|L|R|L|R|L|R|L|R|L|R|L|L|L|R|L |L|R|L|L|R|L ---------------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+- Ambiens | | | | | | | | | | | | | | | | | | | | | | | origin partly fleshy | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Vastus lateralis | | | | | | | | | | | | | | | | | | | | | | | no vincula | | | | | | | | | | | |x| |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extensor iliofibularis | | | | | | | | | | | | | | | | | | | | | | | insertional tendon double | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Piriformis | | | | | | | | | | | | | | | | | | | | | | | posteroproximal corner | | | | | | | | | | | | | | | | | | | | | | | tendinous | |x| | | | | | | | |x| | | |x|x| |x| | | | | insertion fused to flexor | | | | | | | | | | | | | | | | | | | | | | | ischiofemoralis | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Iliotrochantericus medius | | | | | | | | | | | | | | | | | | | | | | | not notched | | | | |x|x| | | | | | | | |x| | | | | | | | anterior part with fleshy | | | | | | | | | | | | | | | | | | | | | | | origin | | | | | | | | | | | | | |x| | | |x| |x| | |x insertion fused to gluteus| | | | | | | | | | | | | | | | | | | | | | | profundus | | | | | | | | | | | | | | | |x| | | | | | | muscle split | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor cruris lateralis | | | | | | | | | | | | | | | | | | | | | | | accessory slip present | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor cruris medialis | | | | | | | | | | | | | | | | | | | | | | | origin from pubis | | | | | | | | | | | | |x| | |x| | | | | | | insertion partly fleshy | | | | | | | | | | | | | | | | | | |x|x| |x|x insertional tendon split | | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | Caudofemoralis | | | | | | | | | | | | | | | | | | | | | | | accessory slip fleshy | |x|x| | | | | | | | | | | | | | | | | | | | tendinous area in belly of| | | | | | | | | | | | | | | | | | | | | | | pars caudifemoralis | | | | | | | | |x|x| | | |x| | | | | | | | | origin from pubis | | | | | | | | | |x| | | | | | | | | | | | | insertion entirely | | | | | | | | | | | | | | | | | | | | | | | tendinous | | | | | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | Flexor ischiofemoralis | | | | | | | | | | | | | | | | | | | | | | | insertion partly fleshy |x| | | | | |x| | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | Adductor superficialis | | | | | | | | | | | | | | | | | | | | | | | groove for flexor cruris | | | | | | | | | | | | | | | | | | | | | | | medialis present | | |x|x| |x| |x| | | | | | | | | | | | | | | completely fused with | | | | | | | | | | | | | | | | | | | | | | | adductor profundus | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adductor profundus | | | | | | | | | | | | | | | | | | | | | | | proximal part of insertion| | | | | | | | | | | | | | | | | | | | | | | tendinous | | | | | | | | | | | | | | | |x| | | | | | | distal end of insertion | | | | | | | | | | | | | | | | | | | | | | | tendinous | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Obturator | | | | | | | | | | | | | | | | | | | | | | | independent slip of pars | | | | | | | | | | | | | | | | | | | | | | | antica present | | | |x| | | | | |x| | | | | | | | | | | | | slip of pars antica fused | | | | | | | | | | | | | | | | | | | | | | | to pars postica | | | | | | |x| | | | | | | | | | | | | |x| | independent slip of pars | | | | | | | | | | | | | | | | | | | | | | | dorsalis present | | | | | | | |x| | | | | | |x|x| | |x| | | | pars dorsalis fused with | | | | | | | | | | | | | | | | | | | | | | | pars antica | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | Gastrocnemius | | | | | | | | | | | | | | | | | | | | | | | pars interna overlaps | | | | | | | | | | | | | | | | | | | | | | | peroneus longus | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor perforans et | | | | | | | | | | | | | | | | | | | | | | | perforatus digiti II | | | | | | | | | | | | | | | | | | | | | | | anterior head entirely | | | | | | | | | | | | | | | | | | | | | | | tendinous | | | | | | | |x| | | | | | | | | | | | | | | vinculum joins flexor | | | | | | | | | | | | | | | | | | | | | | | perforatus digiti II |x| | | | | | | | | | | | | | | | | | | | | | origin from superficial | | | | | | | | | | | | | | | | | | | | | | | surface of patellar | | | | | | | | | | | | | | | | | | | | | | | tendon | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor perforans et | | | | | | | | | | | | | | | | | | | | | | | perforatus digiti III | | | | | | | | | | | | | | | | | | | | | | | accessory head present | | | | |x|x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor perforatus digiti II| | | | | | | | | | | | | | | | | | | | | | | roof of hypotarsal canal | | | | | | | | | | | | | | | | | | | | | | | bony | | | | | | | | |x| | | | | | | | | | | |x|x| | | | | | | | | | | | | | | | | | | | | | | | Plantaris | | | | | | | | | | | | | | | | | | | | | | | accessory head present | | | | |x| | | | | | | | | | | | | | | | | | origin from medial | | | | | | | | | | | | | | | | | | | | | | | collateral ligament | | | | | | | | | | | | | | | | |x | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flexor digitorum longus | | | | | | | | | | | | | | | | | | | | | | | notched for peroneal nerve| | |x|x| | |x|x| | | | | | | | | | | | | |x| origin from tendon of | | | | | | | | | | | | | | | | | | | | | | | extensor iliofibularis | | | | | |x| | | | | | | | | | | | | | | | | third dorsal slip present | | | | | | | | | | | | | | | | | | | | | | | in digit IV | | |x|x| | | | | | | | | | |x|x|x | |x|x|x|x| third dorsal slip present | | | | | | | | | | | | | | | | | | | | | | | in digit III | | |x|x|x| | | | | | | |x|x|x|x|x |x|x| | |x|x second dorsal slip present| | | | | | | | | | | | | | | | | | | | | | | in digit II | | |x|x|x| | | | | | |x| |x|x|x|x |x|x| | |x|x vinculum joins flexor | | | | | | | | | | | | | | | | | | | | | | | perforatus digiti IV | | | | | | | | | | | | | | | | | | | |x|x|x|x | | | | | | | | | | | | | | | | | | | | | | | Peroneus longus | | | | | | | | | | | | | | | | | | | | | | | origin from patellar | | | | | | | | | | | | | | | | | | | | | | | tendon |x|x| | |x|x| | | | | | | | | | | | | | | | |x | | | | | | | | | | | | | | | | | | | | | | | Tibialis anticus | | | | | | | | | | | | | | | | | | | | | | | accessory insertion absent| | | | | | |x| | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | Extensor digitorum longus | | | | | | | | | | | | | | | | | | | | | | | lateral branch of tendon | | | | | | | | | | | | | | | | | | | | | | | not ossified |x| | | |x|x| |x| | | | | | | | | |x|x|x|x|x|x origin from posterior | | | | | | | | | | | | | | | | | | | | | | | surface of outer cnemial| | | | | | | | | | | | | | | | | | | | | | | crest | | | | | | | | | | | | | | | | | |x| x | | |x | | | | | | | | | | | | | | | | | | | | | | | Extensor hallucis longus | | | | | | | | | | | | | | | | | | | | | | | origin lateral to | | | | | | | | | | | | | | | | | | | | | | | retinaculum | |x| | | | | | | | | | | | | | | |x| | | | | distal fibers of distal | | | | | | | | | | | | | | | | | | | | | | | head insert | | | | | | | | | | | | | | | | | | | | | | | independently | | | | |x| | | | | | | | | | | | |x|x| |x| |x accessory bundle present | | | | | | | | | | | | | | |x| | | | | | | | entire distal head inserts| | | | | | | | | | | | | | | | | | | | | | | independently | | | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | Abductor digiti II | | | | | | | | | | | | | | | | | | | | | | | accessory insertion | | | | | | | | | | | | | | | | | | | | | | | present | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extensor proprius digiti | | | | | | | | | | | | | | | | | | | | | | | III present | | | | | | | | | | | | | | | | | |x| | | | |x ---------------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-

TABLE 4. NUMBER OF MUSCULAR VARIATIONS IN COMMON BETWEEN THE LEGS STUDIED

=========+========+===============++===========++======++===========+===== | Other | T.p. || T.c.p. ||T.c.a.|| P.p. | | leg +---------------++-----------++------++-----------+ No Leg |of same |1|1|2|2|3|3|4|5||1|1|2|2|3|4||1|1|2 ||1|1|2|3|3|4|other |specimen|L|R|L|R|L|R|L|R||L|R|L|R|L|L||L|R|L ||L|R|L|L|R|L| legs ---------+--------+-+-+-+-+-+-+-+-++-+-+-+-+-+-++-+-+--++-+-+-+-+-+-+----- T.p. 1L | 1 |-|-| | |2|2|1|1|| | | | | | || | | ||1|1|2|1|1|2| 1 T.p. 2R | 6 | | |-|-|2|1|1|2|| |1| |1|1|2||3|3|3 ||2|3|1|1|4|2| 0 T.p. 3L | 4 |2|1|2|2|-|-| |1|| | | |1|1|2||3|2|2 ||4|4|1|2|3|5| 1 T.c.p. 1R| 1 | | | |1| | | | ||-|-| | | |1|| | | || | | | | | | 2 T.c.p. 2R| 0 | |1|1|1|1| | | || | |-|-| |2||1| |1 ||1|1| | |1|1| 3 T.c.a. 1R| 5 | |2|3|3|2| | |1|| | |1|1|2|2||-|1|3 ||3|4|1|1|3|2| 3 P.p. 1L | 4 | | |2|2|3| |2| || | |1|1|1|3||3|-|2 ||-|-|3|2|3|7| 2 P.p. 3R | 4 | | |4|4|2| | |1||1| | |1|1|2||3|3|3 ||3|5|4|-|-|5| 1 ---------+--------+-+-+-+-+-+-+-+-++-+-+-+-+-+-++-+-+--++-+-+-+-+-+-+-----

TABLE 5. OCCURRENCE OF INDIVIDUAL VARIATIONS IN NERVES

===========================+===============+===========+======+=========== | T.p. | T.c.p. |T.c.a.| P.p. +---------------+-----------+------+----------- |1|1|2|2|3|3|4|5|1|1|2|2|3|4|1|1|2 |1|1|2|3|3|4 |L|R|L|R|L|R|L|R|L|R|L|R|L|L|L|R|L |L|R|L|L|R|L ---------------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+- Lumbosacral plexus | | | | | | | | | | | | | | | | | | | | | | | two fureal nerves | | |x|x| | | | | | | | | | |x|x| | | | |x|x|x S9 with three branches | | | | | | | |x| | | | | | | | | | | | | | | prefixed | | | | | | | | | | | | |x| |x|x|x | | |x|x|x|x sciatic nerve with six | | | | | | | | | | | | | | | | | | | | | | | roots | | |x|x| | | | | | | | |x| |x|x|x | | |x|x|x|x obturator nerve from S2 | | | | | | | | | | | | | | | | | | | | | | | and S3 only | | | | | | | | | | | | | | | | |x | | | |x|x|x femoral nerve mainly from | | | | | | | | | | | | | | | | | | | | | | | S2-S4 | | | | | | | | | | | | |x| |x|x|x | | |x|x|x|x | | | | | | | | | | | | | | | | | | | | | | | Femoral nerve | | | | | | | | | | | | | | | | | | | | | | | anterior division | | | | | | | | | | | | | | | | | | | | | | | innervates | | | | | | | | | | | | | | | | | | | | | | | extensor iliotibialis | | | | | | | | | | | | | | | | | | | | | | | lateralis | | | | | | |x|x| |x|x| |x| | | | | | | | | | dorsal division fused with| | | | | | | | | | | | | | | | | | | | | | | anterior division |x| | | | | | | | | | | | | | | | | |x| |x| |x dorsal division fused with| | | | | | | | | | | | | | | | | | | | | | | middle division | | |x|x| |x| | | | | | | | |x| | | | |x|x| | two branches to iliacus | | |x| | | | | | | | | | | | | | | | | |x| | middle division anasto- | | | | | | | | | | | | | | | | | | | | | | | moses with anterior | | | | | | | | | | | | | | | | | | | | | | | division | | |x|x| | | | | | | | | |x|x|x| | | | | | | anterodorsal division does| | | | | | | | | | | | | | | | | | | | | | | not go through femoral | | | | | | | | | | | | | | | | | | | | | | | notch | | | | |x|x| | | | | | | | | | | | | | | | | branch of anterior divi- | | | | | | | | | | | | | | | | | | | | | | | sion perforates iliacus | | | | | | | | | | | | | | | |x| | | | | | | cutaneous branch perfo- | | | | | | | | | | | | | | | | | | | | | | | rates extensor ilioti- | | | | | | | | | | | | | | | | | | | | | | | bialis lateralis | | | | | | | | | | |x|x| | | | | | | | | | | branch of middle division | | | | | | | | | | | | | | | | | | | | | | | perforates vastus | | | | | | | | | | | | | | | | | | | | | | | medialis | | | | | | | | | | | | | |x| | | | | | | | | branch to vasti innervates| | | | | | | | | | | | | | | | | | | | | | | extensor iliotibialis | | | | | | | | | | | | | | | | | | | | | | | lateralis | | | | | | | | | | |x| | | | | | | | | | | | anterior branch of ante- | | | | | | | | | | | | | | | | | | | | | | | rior division cutaneous | | | | | | | | | | | | | | | | | |x|x| | | |x | | | | | | | | | | | | | | | | | | | | | | | Sciatic nerve | | | | | | | | | | | | | | | | | | | | | | | twig to pars caudifemora- | | | | | | | | | | | | | | | | | | | | | | | lis independent | | |x| | | | | | | | | | | | | | | | | | | | branch to flexor cruris | | | | | | | | | | | | | | | | | | | | | | | lateralis does not | | | | | | | | | | | | | | | | | | | | | | | perforate caudofemoralis|x|x| |x| | | | |x|x|x|x|x| | | |x | | | | | | paraperoneal nerve enters | | | | | | | | | | | | | | | | | | | | | | | peroneal sheath |x| |x|x| | |x| | | | | | | | | | |x|x| | | | cutaneous peroneal branch | | | | | | | | | | | | | | | | | | | | | | | perforates gastrocnemius| | | | | | | | | | | | | | | | | | | | | | | pars externa | | | | | | |x| | | | | | | | | | | | | | | | cutaneous peroneal branch | | | | | | | | | | | | | | | | | | | | | | | absent | | |x|x| | | |x| | | | | | | | | | | | | | | distal cutaneous tibial | | | | | | | | | | | | | | | | | | | | | | | branch absent | | | | | | | |x| | | | | | | | | | | | | | | twig to tail present | | |x| | |x| |x| | | | | | | |x|x | |x| | |x| nonmuscular peroneal twig | | | | | | | | | | | | | | | | | | | | | | | deep to vastus lateralis| | | | | | | | | | | | | | | | | | | | | | | pars postica | | |x|x| | | |x| | | | | | | | |x | | | | | | branch to flexor cruris | | | | | | | | | | | | | | | | | | | | | | | medialis from posterior | | | | | | | | | | | | | | | | | | | | | | | tibial division | | | | | | | | | | | | |x| | | | |x|x| | | | extra twigs join cutaneous| | | | | | | | | | | | | | | | | | | | | | | tibial branches | | | | | | | | | | | | |x| | | | | | | | | | branch to flexor cruris | | | | | | | | | | | | | | | | | | | | | | | medialis an independent | | | | | | | | | | | | | | | | | | | | | | | division | | | | | | | | | | | | | | | | | | | |x|x|x| branch to flexor cruris | | | | | | | | | | | | | | | | | | | | | | | medialis perforates | | | | | | | | | | | | | | | | | | | | | | | flexor | | | | | | | | | | | | | | | | | | | | | | | ischiofemoralis | | | | | | | | | | | | | | | | | | |x| | | | two twigs to flexor | | | | | | | | | | | | | | | | | | | | | | | ischiofemoralis | | | | | | | | | | | | | | | | | | |x|x|x|x|x independent extra branch | | | | | | | | | | | | | | | | | | | | | | | innervates extensor | | | | | | | | | | | | | | | | | | | | | | | iliofibularis | | | | | | | | | | | | | | | | | | | | |x| | branch to femorocruralis | | | | | | | | | | | | | | | | | | | | | | | innervates gastrocnemius| | | | | | | | | | | | | | | | | | | | | | | pars media | | | | | | | | | | | | | | | | | | | | | |x| | | | | | | | | | | | | | | | | | | | | | | | Peroneal nerve | | | | | | | | | | | | | | | | | | | | | | | superficial and deep | | | | | | | | | | | | | | | | | | | | | | | peroneal nerves do not | | | | | | | | | | | | | | | | | | | | | | | join |x| | | |x| |x|x| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tibial nerve | | | | | | | | | | | | | | | | | | | | | | | independent extra branch | | | | | | | | | | | | | | | | | | | | | | | innervates flexor | | | | | | | | | | | | | | | | | | | | | | | perforatus digiti IV | | | | |x|x| | | | | | | | | | | | | | | | | anastomosis involving | | | | | | | | | | | | | | | | | | | | | | | posterior division | | | | |x|x| | | | | | | | | | | | | | | | | branch to gastrocnemius | | | | | | | | | | | | | | | | | | | | | | | pars externa an | | | | | | | | | | | | | | | | | | | | | | | independent division | | | | | |x| | | | | | | | | | | | | | | | | branch to gastrocnemius | | | | | | | | | | | | | | | | | | | | | | | pars media innervates | | | | | | | | | | | | | | | | | | | | | | | femorocruralis |x| | | | |x| | | | | | | | | | | | | | | | | extra branch innervates | | | | | | | | | | | | | | | | | | | | | | | flexor perforatus | | | | | | | | | | | | | | | | | | | | | | | digiti III | | | | | | | | | | | | | | | |x| | | | | | | branch to gastrocnemius | | | | | | | | | | | | | | | | | | | | | | | pars interna perforates | | | | | | | | | | | | | | | | | | | | | | | plantaris | | | | | | | | | | | | | | |x| | | | | | | | branch to gastrocnemius | | | | | | | | | | | | | | | | | | | | | | | pars interna innervates | | | | | | | | | | | | | | | | | | | | | | | plantaris | | | | | | | | | | | | | | | | | | | | |x| | ---------------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-

TABLE 6. NUMBER OF NERVE VARIATIONS IN COMMON BETWEEN THE LEGS STUDIED

=========+========+===============++===========++======++===========+===== | Other | T.p. || T.c.p. ||T.c.a.|| P.p. | | leg +---------------++-----------++------++-----------+ No Leg |of same |1|1|2|2|3|3|4|5||1|1|2|2|3|4||1|1|2 ||1|1|2|3|3|4|other |specimen|L|R|L|R|L|R|L|R||L|R|L|R|L|L||L|R|L ||L|R|L|L|R|L| legs ---------+--------+-+-+-+-+-+-+-+-++-+-+-+-+-+-++-+-+--++-+-+-+-+-+-+----- T.p. 1L | 1 |-|-|1|2|1|1|2|1||1|1|1|1|1| || | |1 ||1|2| |1| |1| 0 T.p. 2L | 5 |1| |-|-| |2|1|3|| | | | | |1||2|2|2 ||1|2|1|2|1| | 1 T.p. 3R | 3 |1| |2|1|-|-| |1|| | | | | | ||1|1|1 || |1|1|1|1| | 1 T.c.p. 1R| 1 |1|1| |1| | |1|1||-|-|2|1|2| || | |1 || | | | | | | 0 T.c.p. 2L| 2 |1|1| |1| | |1|1||1|2|-|-|2| || | |1 || | | | | | | 1 T.c.a. 1R| 1 | | |2|1| |1| |1|| | | | | |1||-|-|1 || |1| | |1| | 2 P.p. 1R | 3 |2| |2|1| |1|1|1|| | | | |1| || |1|1 ||-|-|1|2|2|3| 1 P.p. 3L | 2 |1| |2|1| |1| | || | | | | | ||1| | || |2|3|-|-|2| 2 ---------+--------+-+-+-+-+-+-+-+-++-+-+-+-+-+-++-+-+--++-+-+-+-+-+-+-----

LITERATURE CITED

APPLETON, A. B.

1928. The muscles and nerves of the post-axial region of the tetrapod thigh. Parts I and II. Jour. Anat., 62(3,4):364-438.

BERGER, A. J.

1952. The comparative functional morphology of the pelvic appendage in three genera of Cuculidae. Amer. Midl. Nat., 47(3):513-605.

BERGER, A. J.

1956. The appendicular myology of the Sandhill Crane, with comparative remarks on the Whooping Crane. Wilson Bull., 68(4):282-304.

BOAS, J. E. V.

1933. Kreuzbein, Becken und Plexus Lumbosacralis der Vögel. Det Kongelige Danske Videnskabernes Selskabs Skrifter. Naturvidenskabelig og Mathematisk Afdeling. 9. række, 5(l):1-74, 15 pls.

CARLSSON, A.

1884. Beiträge zur Kenntniss der Anatomie der Schwimmvögel. Bihang till K. Svenska Vetenskapsakad. Handlingar, 9(3):1-44, 5 pls.

CHOMIAK, M.

1950. [Studies on the plexus lumbalis et sacralis in the domestic hen.] Ann. Univ. Mariae Curie-Sklodowska, Lublin, Sect. DD-Vet. Med., 5(3):29-45.

FISHER, H. I.

1946. Adaptations and comparative anatomy of the locomotor apparatus of new world vultures. Amer. Midi. Nat., 35(3):545-727, 13 pls.

FISHER, H. I., and GOODMAN, D. C.

1955. The myology of the Whooping Crane, _Grus americana_. Ill. Biol. Mono., 24(2):viii + 1-127.

GADOW, H.

1880. Zur vergleichenden Anatomie der Muskulatur des Beckens und der hinteren Gliedmasse der Ratiten. Fischer, Jena, 56 pp., 5 pls.

GADOW, H. (with E. Selenka).

1891. Vögel. I. Anatomischer Theil. _In_ Bronn's Klassen und Ordnungen des Their-Reichs, 6(4):1-1008. Winter, Leipzig.

HOLMES, E. B.

1962. The terminology of the short extensor muscles of the third toe in birds. Auk, 79(3):485-488.

HOWARD, H.

1929. The avifauna of Emeryville shellmound. Univ. Calif. Publ. Zool., 32(2):301-394, 4 pls.

HOWELL, A. B.

1938. Muscles of the avian hip and thigh. Auk, 55(1):71-81.

HUDSON, G. E.

1937. Studies on the muscles of the pelvic appendage in birds. Amer. Midl. Nat., 18(1):1-108, incl. 26 pls.

HUDSON, G. E., _et al._

1959. Muscles of the pelvic limb in galliform birds. Amer. Midl. Nat., 61(1):1-67.

JHERING (IHERING), H. V.

1878. Das peripherische Nervensystem der Wirbelthiere. Vogel, Leipzig, xiv-238 pp., 5 pls.

MAN, J. G. DE

1873. Vergelijkende myologische en neurologische Studien over Amphibien en Vögels. van Doesburgh, Leiden, 148 pp., 4 pls.

ROMER, A. S.

1927. The development of the thigh musculature of the chick. Jour. Morph., 43(2):347-385.

SUDILOVSKAYA, A. M.

1931. [Study on the comparative anatomy of the musculature and innervation of the pelvic region and the hind appendages of the Ratitae (_Struthio_, _Rhea_, _Dromaeus_).] Acad. Sci. U.S.S.R., Leningrad, 84 pp. (In Russian.)

TOIT, P. J. DU

1913. Untersuchungen über das Synsacrum und den Schwanz von _Gallus domesticus_ nebst Beobachtungen über Schwanzlosigkeit bei Kaulhühnern. Jenaische Zeitschr. Naturw., 49:149-312, 3 pls.

WILCOX, H. H., JR.

1948. The pelvic musculature of the loon (_Gavia immer_). Univ. Microfilms, Ann Arbor, 95 pp., 26 pls.

WORTHAM, R. A.

1948. The development of the muscles and tendons in the lower leg and foot of chick embryos. Jour. Morph., 83(1):105-148.

YASUDA, M., _et al._

1959. [Comparative and topographical anatomy of the fowl. XI. On the nervous supply of the hind limb.] _In_ Proc. of 47th Meeting of Jap. Soc. of Vet. Sci. Jap. Jour. Vet. Sci., 21(6):36. (Japanese abstract.)

_Transmitted October 30, 1962._

29-5835

(Continued from inside of front cover)

18. Conspecificity of two pocket mice, Perognathus goldmani and P. artus. By E. Raymond Hall and Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January 14, 1960.

19. Records of harvest mice, Reithrodontomys, from Central America, with description of a new subspecies from Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp. 519-529. January 14, 1960.

20. Small carnivores from San Josecito Cave (Pleistocene), Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1 figure in text. January 14, 1960.

21. Pleistocene pocket gophers from San Josecito Cave, Nuevo León, México. By Robert J. Russell. Pp. 539-548, 1 figure in text. January 14, 1960.

22. Review of the insectivores of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 549-578, February 23, 1960.

23. Speciation and evolution of the pygmy mice, genus Baimoys. By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in text. June 16, 1960.

Index. Pp. 671-690

Vol. 10. 1. Studies of birds killed in nocturnal migration. By Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6 figures in text, 2 tables. September 12, 1956.

2. Comparative breeding behavior of Ammospiza caudacuta and A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1 figure. December 20, 1956.

3. The forest habitat of the University of Kansas Natural History Reservation. By Henry S. Fitch and Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4 tables. December 31, 1956.

4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129-161, 8 figures in text, 4 tables. December 19, 1957.

5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163-211, plates 9-10, 1 figure in text. March 12, 1958.

*6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures in text, 35 tables. November 7, 1958.

7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3 figures in text. May 4, 1959.

8. Natural history of the salamander, Aneides hardyi. By Richard F. Johnston and Gerhard A. Schad. Pp. 573-585. October 8, 1959.

9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. By William E. Duellman. Pp. 587-598, 2 figures in text. May 2, 1960.

10. A taxonomic study of the middle American snake, Pituophis deppei. By William E. Duellman. Pp. 599-610, 1 plate, 1 figure in text. May 2, 1960.

Index. Pp. 611-626.

Vol. 11. Nos. 1-10 and index. Pp. 1-703, 1958-1960.

Vol. 12. 1. Functional morphology of three bats: Sumops, Myotis, Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24 figures in text. July 8, 1959.

*2. The ancestry of modern Amphibia: a review of the evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959.

3. The baculum in microtine rodents. By Sydney Anderson. Pp. 181-216, 49 figures in text. February 19, 1960.

*4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960.

5. Natural history of the bell vireo. By Jon C. Barlow. Pp. 241-296, 6 figures in text. March 7, 1962.

6. Two new pelycosaurs from the lower Permian of Oklahoma. By Richard C. Fox. Pp. 297-307, 6 figures in text. May 21, 1962.

7. Vertebrates from the barrier island of Tamaulipas, México. By Robert K. Selander, Richard F. Johnston, B. J. Wilks, and Gerald G. Raun. Pp. 309-345, pls. 5-8. June 18, 1962.

8. Teeth of Edestid sharks. By Theodore H. Eaton, Jr. Pp. 347-362, 10 figures in text. October 1, 1962.

9. Variation in the muscles and nerves of the leg in two genera of grouse (Tympanuchus and Pedioecetes). By E. Bruce Holmes. Pp. 363-474, 20 figs. October 25, 1963.

More numbers will appear in volume 12.

Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960.

2. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figures in text. August 16, 1960.

3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahulia, México. By John M. Legler. Pp. 73-84, pls. 9-12, 3 figures in text. August 16, 1960.

4. Autecology of the copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960.

5. Occurrence of the garter snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in text. February 10, 1961.

6. Fishes of the Wakarusa river in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure in text. February 10, 1961.

7. Geographic variation in the North American cyprinid fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures in text. February 10, 1961.

(Continued on outside of back cover)

(Continued from inside of back cover)

8. Decriptions of two species of frogs, genus Ptychohyla; studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pl. 25, 2 figures in text. April 27, 1961.

9. Fish populations, following a drought, in the Neosho and Marais des Cygnes rivers of Kansas. By James Everett Deacon. Pp. 359-427, pls. 26-30, 8 figs. August 11, 1961.

10. Recent soft-shelled turtles of North America (family Trionychidae). By obert G. Webb. Pp. 429-611, pls. 31-54, 24 figures in text. February 16, 1962.

Index. Pp. 613-624.

Vol. 14. 1. Neotropical bats, from western Mexico. By Sydney Anderson. Pp. 1-8. October 24, 1960.

2. Geographic variation in the harvest mouse, Reithrodontomys megalotis, on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr., and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961.

3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1 and 2, 3 figures in text. July 24, 1961.

4. A new subspecies of the black myotis (bat) from eastern Mexico. By E. Raymond Hall and Ticul Alvarez. Pp. 69-72, 1 figure in text. December 29, 1961.

5. North American yellow bats, "Dasypterus," and a list of the named kinds of the genus Lasiurus Gray. By E. Raymond Hall and J. Knox Jones, Jr. Pp. 73-98, 4 figures in text. December 29, 1961.

6. Natural history of the brush mouse (Peromyscus boylii) in Kansas with description of a new subspecies. By Charles A. Long. Pp. 99-111, 1 figure in text. December 29, 1961.

7. Taxonomic status of some mice of the Peromyscus boylii group in eastern Mexico, with description of a new subspecies. By Ticul Alvarez. Pp. 113-120, 1 figure in text. December 29, 1961.

8. A new subspecies of ground squirrel (Spermophilus spilosoma) from Tamaulipas, Mexico. By Ticul Alvarez. Pp. 121-124. March 7, 1962.

9. Taxonomic status of the free-tailed bat, Tadarida yucatanica Miller. By J. Knox Jones, Jr., and Ticul Alvarez. Pp. 125-133,1 figure in text. March 7, 1962.

10. A new doglike carnivore, genus Cynaretus, from the Clarendonian Pliocene, of Texas. By E. Raymond Hall and Walter W. Dalquest. Pp. 135-138, 2 figures in text. April 30, 1962.

11. A new subspecies of wood rat (Neotoma) from northeastern Mexico. By Ticul Alvarez. Pp. 139-143. April 30, 1962.

12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox Jones, Jr., Ticul Alvarez, and M. Raymond Lee. Pp. 145-159, 1 figure in text. May 18, 1962.

13. A new bat (Myotis) from Mexico. By E. Raymond Hall. Pp. 161-164, 1 figure in text. May 21, 1962.

14. The mammals of Veracruz. By E. Raymond Hall and Walter W. Dalquest. Pp. 165-362, 2 figures. May 20, 1963.

15. The recent mammals of Tamaulipas, Mexico. By Ticul Alvarez. Pp. 363-473, 5 figures in text. May 20, 1963.

More numbers will appear in volume 14.

Vol. 15. 1. The amphibians and reptiles of Michoacán, Mexico. By William E. Duellman. Pp. 1-148, pls. 1-6, 11 figures in text. December 20, 1961.

2. Some reptiles and amphibians from Korea. By Robert G. Webb, J. Knox Jones, Jr., and George W. Byers. Pp. 149-173. January 31, 1962.

3. A new species of frog (Genus Tomodactylus) from western Mexico. By Robert G. Webb. Pp. 175-181, 1 figure in text. March 7, 1962.

4. Type specimens of amphibians and reptiles in the Museum of Natural History, the University of Kansas. By William E. Duellman and Barbara Berg. Pp. 183-204. October 26, 1962.

5. Amphibians and Reptiles of the Rainforests of Southern El Petén, Guatemala. By William E. Duellman. Pp. 205-249, pls. 7-10, 6 figures in text. October 4, 1963.

6. A revision of snakes of the genus Conophis (Family Colubridae, from Middle America). By John Wellman. Pp. 251-295, 9 figures in text. October 4, 1963.

7. A review of the Middle American tree frogs of the genus Ptychohyla. By William E. Duellman. Pp. 297-349, pls. 11-18, 7 figures in text. October 18, 1963.

More numbers will appear in volume 15.

Transcriber's note: List of Illustrations was added during transcription.