Part 39

_Skull and teeth._--Male (based on six adults from Stanford Univ. and vicinity): See measurements and plates 22-24; weight (four adults), 5.4 (5.0-5.9) grams; basilar length, 47 (46.1-48.1); zygomatic breadth more than distance between condylar foramen and M1, or than between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth more than postpalatal length; postorbital breadth less than length of upper premolars (less than distance between posterior borders of P4 and P2) and less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth not greater than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; least width of palate less than lateral length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 or 4 (including I3) upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more or less than (about equal to) length of lower molar and premolar tooth-row and longer or shorter (usually shorter) than rostrum; anterior margin of masseteric fossa below anterior half of m2.

Female (based on three adults, Hayward, Palo Alto, and Morro): See measurements and plates 34-36; weight (no. 43574, from Morro) 2.7 grams; basilar length, 41.2 (40.2-42.2); zygomatic breadth more or less than distance between condylar foramen and M1 and more or less than distance between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate less than lateral length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 (including I3) upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer or shorter than rostrum.

The skull of the female averages 50 per cent lighter than that of the average male.

Comparisons of the skull of the male with those of _M. f. latirostra_, _pulchra_, _xanthogenys_, and _munda_ are made in the accounts of those subspecies.

_Remarks._--Like _M. f. latirostra_, _nigriauris_ long bore the name _xanthogenys_. The fairly adequate lot of specimens is divided between the collections of several institutions. The most satisfactory material in any one collection is in the Stanford University Natural History Museum where local specimens have been accumulated over a period of many years.

No actual intergrade between _nigriauris_ and _xanthogenys_ has been seen, although the specimens from Los Banos, referred to _xanthogenys_, have large skulls as in _nigriauris_. Intergradation with _latirostra_ is shown by specimens, referred to _latirostra_, from the Los Angeles area. Also the one adult male from 5 miles southeast of Santa Margarita, San Luis Obispo County, is of small size and in this respect approaches _latirostra_. The range of _nigriauris_ is separated from that of _munda_ by San Francisco Bay, Carquinez Straits, and I suppose by the lower part of the San Joaquin River. On the basis of color of the inside of the pinna of the ear, the two subspecies are uniformly distinct. Intergradation is assumed to occur through the subspecies _xanthogenys_.

None of the 26 adult and subadult specimens examined for evidences of infestation of the frontal sinuses by parasites shows malformation of the sinuses.

_Specimens examined._--Total number, 103, arranged by counties from north to south. Unless otherwise indicated specimens are in the Museum of Vertebrate Zoölogy.

=California.= _Contra Costa County_: Glen Frazer Station, 1; 2 mi. W Pinole, 1[13]; 1 mi. E Pinole, 1; Richmond, 1[13]; Lafayette, 1; 7 mi. E Clayton, 1; Moraga Valley, 1; Pinehurst, Redwood Canyon, 1; Concord, 1. _Alameda County_: Berkeley, 11; Oakland, 1; Piedmont, 1; Haywards, 2; near Haywards, 2; 10 mi. E Haywards, 1[91]; Redwood Canyon, 1; Calaveras Dam, 1. _San Francisco County_: San Francisco, 11 (5[8], 2[91], 1[60], 1[7]); Ocean View, 1[68]; Visitation Valley, 1. _San Mateo County_: Moss Beach, 1; Half Moon Bay, 1; Redwood City, 1[87]; Menlo Park, 9 (5[87], 2[68]); no locality more definite than county, 1[8]. _Santa Clara County_: 1/4 mi. N Milpitas, 1; 1/4 mi. S Milpitas, 1; Stanford University, 6 (4[68], 2[91]); Palo Alto, 11 (6[41], 2[60], 1[75], 1[87]). _Santa Cruz County_: 3 mi. E Santa Cruz, 1; 2-1/2 mi. E Santa Cruz, 1; Santa Cruz, 6 (2[91], 1[68], 1[4]). _Monterey County_: 1 mi. E mouth Salinas River, 10 ft., 1[37]; Pacific Grove, 1[8]; Monterey, 2 (1[7]); Carmel, 1[8]; Carmel Valley, 1[68]; Point Lobos, 1; Gonzales, 1. _San Luis Obispo County_: 5 mi. SE Santa Margarita, 1; Morro, 1[91]; 3-1/2 mi. S Oceano, 6. _Santa Barbara County_: Santa Maria, 1[87]; 5 mi. N Las Cruces, 1; 7 mi. W Gaviota, 1; Gaviota, 1.

=Mustela frenata latirostra= Hall

Long-tailed Weasel

Plates 1, 22, 23, 24, 34, 35 and 36

_Mustela frenata latirostra_ Hall, Carnegie Instit. Washington Publ. 473:96, November 20, 1936.

_Putorius xanthogenys_, Baird, Mamm. N. Amer., p. 176, 1858 (part); Stephens, California mammals, p. 246, 1906; Merriam, N. Amer. Fauna, 11:25, June 30, 1896 (part).

_Putorius (Gale) brasilianus frenatus_, Coues, Fur-bearing animals, p. 142 (part).

_Mustela xanthogenys xanthogenys_, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912; Grinnell, Univ. California Publ. Zoöl., 40:102, September 26, 1933.

_Mustela arizonensis_, Grinnell and Swarth, Univ. California Publ. Zoöl. 10, 376, October 31, 1913.

_Type._--Male, adult, skull and skin; no. 3257, Mus. Vert. Zoöl.; San Diego, San Diego County, California; May 20, 1907; obtained by Frank X. Holzner.

Right M1 is missing and the part of the jaw bearing this tooth is broken away. With this exception the skull is complete and unbroken and the teeth are all present and entire. The skin is fairly well made and in good condition except that it is slightly soiled.

_Range._--Altitudinally sea level to 8000 feet (Tahquitz Valley, San Jacinto Mountains); Sonoran and Transition life-zones of coast and mountains west of Mohave and Imperial deserts of southern California from Point Conception and Cuyama Valley southward at least to Mexican boundary. See figures 29 and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f. nigriauris_ by having postorbital breadth of adult males and females, more, rather than less, than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; from _M. f. pulchra_ by having tympanic bulla longer than rostrum (orbitonasal length) and by near (_l_) Antique Brown rather than near (16 _j_) Buckthorn Brown to near (_h_) Yellow Ocher color of upper parts.

_Description._--_Size._--Male: Six adults and subadults from San Diego yield average and extreme measurements as follows: Total length, 439 (428-449); length of tail, 153 (142-160); length of hind foot, 45 (40-47). Corresponding measurements for a series of eight adult males from the vicinity of Los Angeles are: 416 (394-428); 158 (151-166); 44 (40-47). In the series from San Diego the tail averages 54 per cent as long as head and body. In the series from Los Angeles the average is 61 per cent. Length of hind foot in each series, less than basal length. The type specimen measures, 435, 142, 42.

Female: No. 5070, adult, from San Diego, measures 367, 141, 38. Nos. 22 and 6748 from Santa Ysabel, measure: 359, 380; 130, 140; 39, 35. No. 7194 from Jamacha measures, 358, 125, 35. Three adult females from Los Angeles yield the following: Total length, 373, 345, 368; length of tail, 150, 122, 134; length of hind foot,--, 41, 41. In no. 5070 the tail is 62 per cent as long as the head and body and in the three from Los Angeles it averages 60 (55-67) per cent. Length of hind foot, in each case, less than basal length.

The average differences in external measurements of the two sexes as shown by the six males from San Diego and the four females from San Diego County are: Total length, 73; length of tail, 19; length of hind foot, 8. Corresponding differences shown by the eight males and three females from Los Angeles are: 54, 23, 3.

_Externals._--Longest facial vibrissae brownish, like dark color of head and extending beyond ear; carpal vibrissae mostly color of underparts and extending to apical pad of fifth digit; hairiness of foot-soles slightly more than shown in figure 20.

_Color._--Spot between eyes, band confluent with color of underparts on each side of head extending anterodorsally anterior to ear, and posterior third of each upper lip tinged with color of underparts or, less often, white; chin and lower lips white; remainder of sides and top of head posteriorly to near line connecting posterior margins of ears, blackish; inside of pinna of ear, and sometimes outside of pinna, blackish; dark spot posterior to each angle of mouth present on each side in three-fourths of specimens; tip of tail black; remainder of upper parts near (_l_) Antique Brown, and with more yellow than tone 3 of Raw Umber of Oberthür and Dauthenay, pl. 301. Underparts Ochraceous-Buff to Warm Buff and in some specimens from Los Angeles and Ventura counties Ochraceous-Orange, especially in young and juveniles. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists and on medial sides of hind limbs over antiplantar faces of toes. Least width of color of underparts averaging, in 15 adult and subadult males from San Diego County, 54 (35-75) per cent of greatest width of color of upper parts. Black tip of tail in same series of males averaging 54.5 (46-60) mm. long. Thus averaging longer than hind foot and 35 per cent of length of tail-vertebrae.

_Skull and teeth._--Male (based on 6 adults from San Diego County). See measurements and plates 22-24. As described in _M. f. nigriauris_ except that: Weight (4 specimens), 3.9 (3.8-4.0) grams; basilar length 43.8 (41.9-47.0); postorbital breadth more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth not less than distance between foramen opticum and anterior margin of tympanic bulla; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 2 to 2-1/2 (including I3) upper incisors; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer than rostrum; anterior margin of masseteric fossa below m2.

Female (based on 4 adults from San Diego County): See measurements. As described in _M. f. nigriauris_ except that: Weight, 2.6 (2.2-2.8) grams; basilar length, 40.0 and 40.1; postorbital breadth more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; length of tympanic bulla more than length of rostrum.

The skull of the female averages 34 per cent lighter than that of the average male.

The skull of the male of _latirostra_, compared with that of _nigriauris_, is by weight, more than one-fourth lighter, has a lesser basilar length, a lesser mastoid breadth, a lesser zygomatic breadth and a narrower M1. In these features no overlap has been observed between adults from the general vicinities of the type localities of the two forms. In adult males of _latirostra_ the postorbital breadth, with one exception, is more than the combined length of P4 and P3 whereas the reverse is true in adult males of _nigriauris_. Both males and females of _latirostra_ have a generally smaller skull with relatively broader interorbital and postorbital parts and the tympanic bullae are relatively larger, rounder and more inflated.

Compared with the skull of the male of _pulchra_ that of _latirostra_ is, by weight, more than one-fourth lighter, has a lesser basilar and orbitonasal length, lesser zygomatic and mastoid breadth and a more nearly flat braincase. In these features no overlap has been observed between adults from the general vicinities of the type localities of the two subspecies. Also, in _latirostra_ the tympanic bulla is longer than the rostrum whereas the opposite is true in _pulchra_. The skull of _latirostra_ is generally smaller and relatively, on the average, has the preorbital part of the skull deeper and broader with longer tooth-rows, although with shorter rostrum, while the zygomatic and mastoid breadths are less. Study of skulls of subadult females of _pulchra_ indicate that females of _latirostra_ and _pulchra_ differ in the same fashion as do males.

_Remarks._--This subspecies long has gone by the name _M. xanthogenys_ and the type locality was generally supposed to be in the vicinity of San Diego. This supposition seems to have originated with Merriam's (1896:25) statement that the type locality was "Southern California, probably vicinity of San Diego." Nevertheless, as set forth in the account of _M. f. xanthogenys_ the type specimen concerned now is thought to have come from much farther north.

Although 76 Recent specimens are available from southern California, additional adults are needed to understand the geographic variation there. _M. f. latirostra_ may be a composite--made up of more than one geographic race. Specimens from San Diego County differ so much in relative length of the tail that at one stage in the present study it was thought that a difference in this respect existed between the coastal animals and those from farther inland. Material received later did not wholly substantiate this view and because of the uniformly small size of all of the skulls from that county, the animals were later regarded as of the same subspecies. Eventually, even this supposed common feature proved to be inconstant for an adult male from Jamacha, no. 7098, of the San Diego Society of Natural History, and another adult male from San Marcos, no. 8869, collection of Ralph Ellis, were later examined and found to have skulls as large as those of average-sized, adult males of _nigriauris_.

Despite these puzzling local variations, it is established that the long-tailed weasels of southern California are smaller than those from farther north. Also, the southern animal averages smaller in weight and size of skull, and the skull is differently proportioned. Specimens in series from Los Angeles County definitely are intermediate in size and shape of skull between _latirostra_ from San Diego County and _nigriauris_ from, say, Santa Clara County, but definitely more closely resemble _latirostra_ from San Diego County than they do _nigriauris_. A skull of a young animal, not here identified to subspecies, from Potholes, in the Colorado River Valley, 10 miles northeast of Bard, Imperial County, California, may have closest relationship to _M. f. latirostra_. Additional comment on this specimen is offered in the account of _M. f. neomexicana_.

From the asphalt pits of Rancho La Brea, in Los Angeles County, a total of 57 skulls have been examined, more than half of which are reasonably complete. I have been unable to learn whether these came from pits regarded by students of the deposit as wholly Recent, from pits regarded as of Pleistocene age, or from both. Suffice to say that only two specimens were found which could be distinguished from skulls of the subspecies of weasel living in that area today.

These two specimens, lent to me by Professor Chester Stock, were with other skulls received from the Los Angeles Museum of History, Art and Science and bore identifying numbers as follows: 16/20-27, the anterior part of the skull of an adult, and 16, the skull posterior to the cribiform plate of a subadult or possibly young individual. The latter has a mastoid breadth of 28.0 millimeters, a tympanic bulla 16.1 long and other measurements in proportion. It is larger than any specimen of weasel, of any subspecies, seen from California and in the subgenus _Mustela_ seems to be exceeded in size only by certain individuals of _M. f. texensis_. _M. f. neomexicana_ attains relatively large size and comparisons were made with individuals of that subspecies. However, the young specimen from Rancho La Brea differs from _neomexicana_ in that the tympanic bullae rise less steeply on the medial sides and the inferior lip of the external auditory meatus is less developed laterally. Age considered, the sagittal crest is less developed and the mastoid processes project more abruptly from the skull. The anterior part of the skull of the adult, no. 16/20-27 is larger than any specimen seen of _M. f. latirostra_ or adjoining subspecies, and among California-taken specimens is equaled in size only by the largest males of _M. f. munda_ from the northwest coastal district in Mendocino County. This adult from Rancho La Brea differs from _neomexicana_, sex and age taken into account, in greater postorbital breadth, lesser rostral width in comparison with the interorbital breadth, and in having the temporal ridges at the anterior end of the sagittal crest spread out into a Y-shaped, rather than a T-shaped, pattern. All these differences from _neomexicana_ are features of agreement with the California bridled weasels of the subspecies _latirostra_, _nigriauris_, and _munda_. The same is true of the characters which set apart the young specimen from _neomexicana_. In summary: of 57 weasel skulls examined from the asphalt pits at Rancho La Brea, Los Angeles County, all but two are indistinguishable from the skulls of the Recent weasel living in that region today. These two skulls agree in qualitative characters with animals of the California coastal subspecies now living from Los Angeles northward to Humboldt County, but are larger. For the time being these two may be thought of as giants of the same type of animal inhabiting the Los Angeles region today.

Only one of 41 adult and subadult skulls examined for malformation of the frontal sinuses shows infestation by parasites.

_Specimens examined._--Total number, 142, listed by counties from north to south. Unless otherwise indicated specimens are in the Museum of Vertebrate Zoölogy.

=California.= _Santa Barbara County_: Rincon Point, 1. _Ventura County_: Cuyama Valley, 2200 ft., 1[91]; Nordhoff, 3[59]; Santa Paula, 1[59]; Ventura, 7. _Los Angeles County_: near Owensmouth, 1[24]; Cahuenga, 1[91]; Llano, 10 mi. E Littlerock, 1; Flint Ridge, Pasadena, 1[59]; Pasadena, 3; Lankershim, 1[24]; 1 mi. S Lankershim, 1[24]; Duarte, 1[59]; Covina, 1[59]; Claremont, 1[91]; El Monte, 4 (2[75], 1[24]); Montebello, 1; Alhambra, 6 (5[2], 1[91]); El Nogal, 2[8]; Gardena, 1[26]; Palos Verdes Estate, 3; Rancho La Brea asphalt deposits, 57[70]^{ and }[92]. _San Bernardino County_: San Bernardino Valley, 1[75]; San Bernardino, 4 (2[20], 1[91]); Redlands, 2 (1[38]); Bluff Lake, 2 (1[59], 1[33]). _Riverside County_: West Riverside, 1; Arlington, 800 ft., 1[17]; 3-1/2 mi. E and 1/2 mi. N Beaumont, 2600 ft., 1; Banning, 1[91]; Cabazon, 1[91]; San Jacinto Plain, 1[20]; Tahquitz Valley, 8000 ft., 1; Elsinore, 1[1]. _San Diego County_: Twin Oaks, 1[91]; San Marcos, 2 (1[87], 1[41]); Escondido, 1; Witch Creek, 1[91]; Ballena, 1[20]; Santa Ysabel, 3 (2[20], 1[87]); Julián, 1; La Jolla, 1; Lakeside, 1[91]; El Cajon, 1[91]; El Vido (not found on map), 1[91]; San Diego, 9 (1[91], 1[20], 1[87], 1[32]); Jamacha, 2[87]; Chula Vista, 1[20].

=Mustela frenata pulchra= Hall

Long-tailed Weasel

Plates 22, 23 and 24

_Mustela frenata pulchra_ Hall, Carnegie Instit. Washington Publ. 473:98, November 20, 1936.

_Type._--Male, adult, skeleton and skin; no. 16668, Mus. Vert. Zoöl.; Buttonwillow, Kern County, California; April 30, 1912; obtained by J. Grinnell; original no. 1953.

The skull (plates 22-24) is complete and unbroken (a fracture in the right jugal has healed). All teeth are present and entire. The skeleton lacks the os penis, left fibula, shaft of left tibia and the distal three or four caudal vertebrae. Some of the bones of the feet distal to the radius and tibia are with the skeleton, and the remainder probably are in the skin. The skin is fairly well made and in good condition, except for the left hind leg which was torn when the animal was captured. A well-developed scrotal pouch shows the specimen to have been a male.

_Range._--Altitudinally around 300 feet in San Joaquin Valley to 2500 feet at Isabella; Upper Sonoran and Lower Sonoran life-zones of southern end of San Joaquin Valley and in mountains at southern end of Valley, California. See figures 29 and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f. nevadensis_ in presence of light facial markings, and from _M. f. nevadensis_ and _M. f. inyoensis_ in near (16 _j_) Buckthorn Brown to near (_h_) Yellow Ocher rather than near (14 _n_ to _l_) Brussels Brown color of upper parts, and greater size with hind foot more than 40 in females and basilar length averaging more than 46.0 in males; from _M. f. latirostra_ in having rostrum (orbitonasal length) longer than tympanic bulla and from _M. f. latirostra_ and _M. f. nigriauris_ by color of upper parts as stated above rather than near (_l_) Antique Brown, and by having inside of ears same color as back rather than much darker than back; from _M. f. xanthogenys_ in hind foot of males more than 46 and broader skull which in males has breadth of rostrum more than 13.9 and mastoid breadth more than 26.0.

_Description._--_Size._--Male: The type specimen and five other adults yield average and extreme measurements as follows: Total length, 454 (428-477); length of tail, 178 (153-184); length of hind foot, 50 (47-55). Tail averages 65 per cent as long as head and body. Length of hind foot approximately equal to basal length. The type specimen measures, 460, 184, 49.

Female: Three subadult topotypes yield average and extreme measurements as follows: Total length, 399 (383-411); length of tail, 154 (140-161); length of hind foot, 42 (41-42). Tail averages 63 per cent as long as head and body. Length of hind foot less than basal length.

The average differences in external measurements of the two sexes are: Total length, 55; length of tail, 24; length of hind foot, 8.

_Externals._--As described in _Mustela frenata nigriauris_.