Part 16

From _alascensis_, _salva_ differs in that males have the preorbital region slightly wider in relation to the length of the tympanic bulla; also the braincase is smaller, actually as well as in comparison with the preorbital part of the skull. The tympanic bullae do not project so far below the squamosals and the braincase itself is shallower, in adults averaging only 11.5 mm. as against 12.5 mm. The overall depth of the braincase, including the tympanic bullae, when divided into the orbitonasal length gives an average of 93 (90-97) per cent whereas in _alascensis_ the figure is only 85 (78-88) per cent. On this basis alone, everyone of the adult skulls of the two races can be distinguished. The females and subadult males show the same tendency to reduction in depth of braincase but not every individual among them can be surely distinguished. By weight the skull of _salva_ of corresponding sex is only about 6 per cent smaller. Comparisons with _initis_ and _celenda_ are made in the accounts of those subspecies.

_Remarks._--Most of the specimens seen were collected by Allen E. Hasselborg, resident on Admiralty Island. On the basis of skulls--few skins, and measurements taken in the flesh, are available--_salva_ more closely resembles _alascensis_ than does any other subspecies so far known from southeastern Alaska. The race on Admiralty Island is only slightly differentiated from _alascensis_ of the adjacent mainland.

_Specimens examined._--Total number, 26, all from Admiralty Island, Alaska, arranged in general by localities from north to south, and unless otherwise indicated in the Museum of Vertebrate Zoölogy, University of California.

=Alaska.= Admiralty Island: Hawk Inlet, 2; Seymour Canal, 4; Mole Harbor, 18 (skulls only); Gambier Bay, 1; no locality more definite than Admiralty Island, 4 (1 in U. S. Nat. Mus.).

=Mustela erminea initis= Hall

Ermine

Plates 4, 5 and 6

_Mustela erminea initis_ Hall, Proc. Biol. Soc. Washington, 57:37, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

_Type._--Male, adult, skull and skin; no. 289, Mus. Vert. Zoöl.; Saook Bay, Baranof Island, Alaska; October 9, 1907; obtained by A. Hasselborg, original no. 4.

The top of the skull is fractured on the left side from the anterior nares posteriorly through the postorbital process to the posterior root of the zygomatic arch. On the left lower jaw the canine and three incisors are missing; otherwise the teeth all are present and entire.

The skin is in process of molt, approximately nine-tenths of the incoming white pelage being in place. The skin is well made and in a good state of preservation.

_Range._--Chichagof and Baranof islands, Alaska. See figures 25, 26 on pages 95, 134.

_Characters for ready recognition_ (only males known).--Differs from _M. e. arctica_, in that proximal two-thirds of under side of tail colored same as upper parts rather than same as underparts, zygomatic breadth less than distance between last upper molar and jugular foramen; from _M. e. salva_ in that orbitonasal length and mastoid breadth total more than 35 mm., weight of skull and lower jaws more than 2.1 grams; from _M. e. alascensis_, by total length more than 317, black tip of tail more than 57 per cent of length of tail-vertebrae, interorbital breadth more than 10.3 and equal to, instead of less than, distance between glenoid fossa and posterior border of external auditory meatus; from _M. e. celenda_ by chest white (not mostly covered by brown patch), breadth of rostrum measured across lacrimal processes less than a third of basilar length; from _M. e. seclusa_ in zygomatic breadth more than distance between last upper molar and jugular foramen.

_Description._--_Size._--Male: The type and an adult topotype measure, respectively, as follows: Total length, 330, 320; length of tail, 95, 95; length of hind foot, 45, 45.

Female: No external measurements available.

_Color._--As described in _Mustela erminea richardsonii_ except that least width of color of underparts averages, in two young female topotypes, 50 (49, 50) per cent of greatest width of color of upper parts. Black tip of tail in three young female topotypes averaging 54 (52-55) mm. which is 67 (63-69) per cent of length of tail-vertebrae.

_Skull._--Male (illustrated by type and 1 ad. topotype): See measurements and plates 4-6. As described in _Mustela erminea richardsonii_ except that: Weight, 2.3 and 2.5 grams; basilar length, 39.6, and 40.5; interorbital breadth equal to distance between glenoid fossa and posterior border of external auditory meatus.

Female: No adults available.

From _salva_, _initis_ differs in that skulls of males average larger in every measurement taken, being 41 per cent heavier. Relative to the basilar length, the interorbital and preorbital parts of the skull are larger; the relatively greater interorbital and mastoid breadths are particularly noticeable. Although the depth of the braincase, including the tympanic bullae, is both relatively as well as actually more than in _salva_, the depth is relatively less than in _alascensis_ which otherwise differs from initis in about the same way that _salva_ differs from _initis_. Whereas the interorbital breadth in _initis_ is about equal to the distance between the glenoid fossa and the posterior border of the external auditory meatus, the interorbital breadth is uniformly less than this distance in both _salva_ and _alascensis_. In comparison with _seclusa_ the teeth are of the same size but all measurements of the skull are larger. The skull of _initis_ is 25 per cent heavier. In relation to the basilar length, the interorbital and preorbital parts of the skull are much less in _initis_. The preorbital and interorbital regions in _initis_ are relatively smaller in comparison also with _arctica_. The one measurement of interorbital breadth in _initis_ is greater in relation to the basilar length than in _kadiacensis_ but the rostral region, and all that part of the skull anterior to the braincase, is relatively smaller in _initis_.

_Remarks._--The two adult males, nos. 286 and 289 from Saook Bay, provide convincing evidence of the existence of a distinct race of weasel on Baranof Island. Three other young specimens, almost subadult, from the same place are labeled as males although the basilar lengths of these skulls are only 35.5, 35.9 and 37.3 millimeters as against 39.6 and 40.5 in the two adult males. The difference in size is too great to be age-variation. The fact that 3 are definitely of one category and 2 of the other makes it doubtful that individual variation accounts for the differences. The small size of these 3 specimens and the fact that in each the anterior margin of the tympanic bulla is flush with the squamosal rather than protruded from the braincase, suggests that the three are females. If they are females, the amount of secondary sexual variation is rather less than would be expected by analogy with the amount obtaining in _alascensis_ on the mainland and in _salva_ on Admiralty Island. Another possibility that I can not disprove is that two stocks of weasels persist on Baranof Island, the two larger specimens being descendants of the stock which first became established on the island and the three smaller specimens being descendants of an individual ermine, or of ermines, that were rafted or otherwise transported to the island at a considerably later date. Assuming for the moment that there are two stocks, it must be admitted that each one differs from any stock known from elsewhere. Therefore, each stock would be presumed to have been long resident on the island. But--two stocks as closely related as the two in question would not be expected to persist for long in an area as small as that of Baranof Island because competition would give one the ascendancy. Therefore, the first suggestion, namely that the three smaller animals are really females, seems the more probable. The feasible way to clear up the present uncertainty is, of course, to obtain additional specimens, carefully labeled as to sex. Yet another reason why additional collecting is desirable in this area is to ascertain whether there is subspecific differentiation between the ermines of Baranof and Chichagof islands. The one specimen available from the latter island, although in general like the three smaller animals from Baranof Island, differs in the fuller (less scooped out) medial side of the tympanic bulla and to a slight degree in each of some other features. This specimen from Chichagof Island is labeled as a male also.

_Specimens examined._--Total number, 6, arranged by localities from north to south, and in the Museum of Vertebrate Zoölogy, University of California.

=Alaska.= Chichagof Island, Freshwater Bay, 1. Baranof Island, Saook Bay, 5.

=Mustela erminea celenda= Hall

Ermine

Plates 5, 6 and 7

_Mustela erminea celenda_ Hall, Proc. Biol. Soc. Washington, 57:38, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

_Type._--Male, adult, skull and skin; no. 130987, U. S. Nat. Mus., Biol. Surv. Coll.; Kasaan Bay, Prince of Wales Island, Alaska; June 16, 1903; obtained by Cyrus Catt; original no. 4407X.

The skull has a piece 1.5 mm. long broken out of the left zygomatic arch. P2 is absent on both sides. The right I1, and the left I1 and I2 are missing. The skin, in summer pelage, is fairly well made. A scrotal pouch attests to the correctness of the sex recorded on the label. The rostral part of the skull is smaller than in average-sized males of corresponding age.

_Range._--Prince of Wales, Dall, and Long islands, Alaska. See figures 25, 26 on pages 95, 134.

_Characters for ready recognition_ (only males known).--Differs from _M. e. alascensis_ and _initis_ in chest mostly covered by brown patch, not white, and breadth of rostrum measured across lacrimal processes more than a third of basilar length, which cranial character serves to distinguish also _salva_; from _M. e. seclusa_ in zygomatic breadth less than distance between last upper molar and jugular foramen; from _M. e. haidarum_ in chest white (not mostly covered by brown patch), proximal two-thirds of underside of tail colored like upper parts rather than underparts, basilar length more than 38.2 mm.

_Description._--_Size._--Male: Seven adults and subadults from Prince of Wales Island, yield average and extreme measurements as follows: Total length, 286 (277-304); length of tail, 77 (74-85); length of hind foot, 36 (35.5-40.5).

Female: No specimen available.

_Color._--As described in _Mustela erminea richardsonii_ except that upper parts about tone 3 of dark Chocolate Brown of Oberthür and Dauthenay, pl. 342; lower throat and chest covered by a large patch of same color as upper parts; color of underparts extending to toes but in interrupted fashion on both fore-and hind-feet; least width of color of underparts averaging, in four males from Prince of Wales Island, 41 (38-49) per cent of greatest width of color of upper parts. Black tip of tail averaging, in 8 males in winter pelage, 65 (59-78) mm. which is 84 (69-92) per cent of length of tail-vertebrae.

From its geographic neighbors _alascensis_ and _initis_, _celenda_ differs in darker color of upper parts, presence rather than absence of patch of dark color on lower throat and chest, and longer black tip on tail. From _haidarum_, _celenda_ differs in darker color of upper parts, presence rather than absence of patch of dark color on lower throat and chest, narrower light-colored under parts, black tip of tail averaging less rather than more than nine-tenths of length of tail-vertebrae and ventral face of tail colored like upper parts rather than like underparts.

_Skull._--Male (illustrated by 5 adults): See measurements and plates 5-7. As described in _Mustela erminea richardsonii_ except that: Weight, 2.3 (2.2-2.5) grams; basilar length, 39.5 (38.9-40.7) mm.; length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more or less than (about equal to) distance between last upper molar and jugular foramen.

Female.--Complete skull of adult unavailable.

Differences from _richardsonii_ are indicated in the formal description just given. Additional to differences therein noted, _celenda_ differs from _initis_ in larger interorbital and preorbital parts of the skull although dimensions of other parts of the skull and the teeth are about the same or even less. From _salva_, _celenda_ differs in larger average size in every measurement taken, except for the inner moiety of M1 which is about the same. The skull of _celenda_ is 35 per cent heavier. In relation to the basilar length the skull of _celenda_ is wider, especially in the interorbital and preorbital regions. In comparison with _alascensis_ the tympanic bullae are of approximately the same length; otherwise essentially the same differences obtain as are noted in comparison with _salva_ and the zygomatic breadth is relatively more in _celenda_. From _seclusa_, in which the teeth are of comparable size, _celenda_ differs in that every cranial measurement is more and the skull is 28 per cent heavier. Because the skull of _celenda_ is so much longer, its dimensions in other planes are less in relation to the length than in _seclusa_. _M. e. celenda_ is larger in every part measured than _haidarum_, 21 per cent heavier, and in relation to the basilar length the interorbital, and preorbital, parts of the skull are smaller, the braincase is shallower, and the skull is relatively wider across the zygomata and mastoid processes. In comparison with _kadiacensis_, differences are: 26 per cent lighter, skull shorter; in relation to the basilar length, braincase shallower as measured at the anterior end of the basioccipital, tooth-rows shorter but orbitonasal length more. In comparison with _arctica_ all parts measured of the teeth and skull of _celenda_ are smaller and its skull is 34 per cent lighter. In relation to the basilar length, the interorbital breadth of _celenda_ is only slightly less but its skull is narrower across the rostrum and zygomata, the tooth-rows are shorter, and the braincase is shallower.

_Remarks._--The late George Willett in the course of his work in Alaska collected most of the known specimens of this strongly differentiated subspecies. In both coloration and cranial characters the distinguishing features are so well marked that the zoölogist could with reason accord full specific rank to _celenda_. Nevertheless it obviously is an ermine. Also, races from other islands of southeastern Alaska tend to bridge the gap, as regards cranial features, between _celenda_ and the mainland ermine. The specimen from Dall Island agrees in all respects with topotypes. The specimen from Howkan on Long Island is in white winter pelage and the skull has suffered shrinkage from some chemical solution; the reference of this specimen to _celenda_ is tentative.

_Specimens examined._--Total number, 25, as follows: Arranged by localities from north to south. Unless otherwise indicated, in U. S. National Museum.

=Alaska.= Prince of Wales Island: Craig, 18 (10 in Mus. Vert. Zoöl., and 8 in Los Angeles Mus. Hist. Art and Sci.); Kasaan Bay, 2; no locality more definite than the Island itself, 3; Dall Island, Otter Harbor, 1 (Los Angeles Mus. Hist. Art and Sci.). Long Island, Howkan, 1 (Field Mus. Nat. Hist.).

=Mustela erminea seclusa= Hall

Ermine

Plates 5, 6 and 7

_Mustela erminea seclusa_ Hall, Proc. Biol. Soc. Washington, 57:39, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

_Type._--Male, adult, skull alone; no. 31232, Mus. Vert. Zoöl.; Port Santa Cruz, Suemez Island, Alaska; March 24, 1920; obtained by George Willett.

The skull (plates 5-7) is complete and unbroken. Of the upper incisors only right I3 is present. Otherwise the teeth are present and unbroken.

_Range._--Known only from the type locality. See figures 25, 26 on pages 95, 134.

_Characters for ready recognition_ (only the male known).--Differs from _M. e. celenda_ in basilar length less than 38.2, from _M. e. salva_, _initis_ and _haidarum_ in zygomatic breadth more than distance between last upper molar and jugular foramen.

_Description.--Size_ and _Color._--No external measurements or skins available.

Skull.--Male: See measurements and plates 5-7. As described in _Mustela erminea richardsonii_ except that: Weight, 1.8 grams; basilar length, 34.3; length of tooth-rows about the same as length of tympanic bulla; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior margin of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.

Female.--Skull not available.

From _alascensis_ and _salva_, _seclusa_ differs in larger teeth, shorter skull, much larger preorbital and interorbital regions, actually as well as in relation to basilar length. Excepting the teeth, which are of about the same size, the same general differences obtain in comparison with _initis_ which, however, is 29 per cent heavier.

From _celenda_, _seclusa_ differs in smaller skull in all parts measured, being 22 per cent lighter. The teeth are about the same size. In relation to its length the skull of _seclusa_ is much broader and deeper. From _haidarum_, _seclusa_ differs in: teeth larger; skull shorter and more convex in dorsal outline along median longitudinal axis; in relation to basilar length, skull broader, deeper and braincase relatively shorter.

_Remarks._--The characters shown in the one available skull are far outside the limits of individual variation for other known subspecies. Other specimens are much to be desired to ascertain what the "average" individual is like and to learn the characters of the female.

_Specimen examined._--One, the holotype.

=Mustela erminea haidarum= (Preble)

Ermine

Plates 5, 6, 7, 11, 12 and 13

_Putorius haidarum_ Preble, Proc. Biol. Soc. Washington, 12:169, August 10, 1898.

_Mustela haidarum_, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.

_Mustela erminea haidarum_, Hall, Proc. Biol. Soc. Washington, 57:38, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

_Type._--Male, adult, skull, skeleton and skin; no. 94430, U. S. Nat. Mus., Biol. Surv. Coll.; Massett, Queen Charlotte Islands, British Columbia; March 17, 1898; obtained by J. H. Keen; original no. 1800x.

The skull is unbroken and complete except for osseous tissue destroyed in the region of each postorbital process; this is the result of infestation of the frontal sinuses by parasites. The skeleton is complete down to the distal ends of the tibiae; the more distal bones are in the skin. The first, right, upper incisor is missing. Otherwise the teeth all are present and entire.

The skin is in the white, winter pelage but the new under fur is visible along the back and on the head although mostly covered with white hair.

_Range._--Queen Charlotte Islands. See figure 25, page 95.

_Characters for ready recognition._--Differs from _M. e. celenda_ in chest white (not mostly covered by brown patch), proximal two-thirds of under side of tail colored like underparts instead of upper parts, in males basilar length less than 38.2; from _M. e. seclusa_, in male, in zygomatic breadth less than distance between last upper molar and jugular foramen; from _M. e. richardsonii_ and _alascensis_, in both sexes, in proximal two-thirds of under side of tail colored like underparts instead of upper parts, interorbital breadth not less than distance from glenoid fossa to posterior margin of external auditory meatus; from _M. e. anguinae_ and _fallenda_, in both sexes, in light-colored underparts more than half the width of dark-colored upper parts, proximal two-thirds of under surface of tail colored like underparts instead of upper parts, interorbital breadth equal to or more than distance between glenoid fossa and posterior margin of external auditory meatus.

_Description.--Size._--Male: Two adults, U.S.N.M., no. 100622, from Cumsheva Inlet, and Amer. Mus. N. H., no. 37411, and the type, measure, respectively, as follows: Total length, 283, 290, 275; length of tail, 70, 75, 60; length of hind foot, 39, 40, 37.

Female: Corresponding measurements of an adult, no. 100624, and a young individual, no. 100623, each from Cumsheva Inlet, are: 252, 250; 63, 61; 31, 32.

_Color._--As described in _Mustela erminea richardsonii_ except that underparts not Sulphur Yellow but ranging from near (_e_) Colonial Buff through Marguerite Yellow to almost pure white; color of underparts extends distally on posterior sides of forelegs and onto toes but in many specimens interrupted at wrist by color of upper parts; color of underparts extends onto proximal three-fourths of under side of tail as length of tail is measured along tail-vertebrae; least width of color of underparts averaging, in 5 males, 79 (66-130) per cent of greatest width of color of upper parts. Black tip of tail in same males averaging 62 (60-70) mm. which is 92 (83-115) per cent of length of tail-vertebrae.

The close correspondence in color-pattern of this weasel with the Arctic races, _arctica_, _polaris_, _semplei_ and _kadiacensis_ is noteworthy, and distinguishes it from weasels on the adjacent mainland and adjoining islands to the north and south. The color of the upper parts is darker than in the four Arctic races named.

_Skull._--Male (7 adults): See measurements and plates 5-7. As described in _Mustela erminea richardsonii_ except that: Weight, 1.9 (1.7-2.0) grams; basilar length, 36.7 (35.6-37.5); length of tooth-rows more than length of tympanic bullae; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior margin of external auditory meatus; zygomatic breadth barely less than distance between last upper molar and jugular foramen.

Female (2 adults): See measurements and plates 11-13. As described in _Mustela erminea richardsonii_ except that: Weight, 1.3 and 1.4 grams; basilar length, 34.2; length of tooth-rows more or less than (about equal to) length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth not less than distance between glenoid fossa and posterior margin of external auditory meatus.