Part 70

The average differences in external measurements between the two sexes, as represented by these six specimens, are: Total length, 65; length of tail, 25; length of hind foot, 3.5. One adult male weighs 274 grams and 2 adult females 182 and 214 grams.

Externals.--As described in Mustela frenata nigriauris.

Color.--Spot between eyes, band confluent with color of underparts on each side of head extending anterodorsally anterior to each ear, and posterior half to third of each upper lip white, or whitish tinged with some shade of yellowish; chin and lower lip white; dark spot posterior to each angle of mouth of varying size but uniformly present; tip of tail black; remainder of upper parts Buckthorn Brown of Ridgway or a trifle browner than tone 4 of Brown Pink of Oberthür and Dauthenay, pl. 297. Upper parts of uniform color except for slight darkening of head-markings anterior to ears. Underparts Ochraceous-Buff to Warm Buff. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind limbs over antiplantar faces of toes and sometimes tarsal region. Least width of color of underparts averaging, in 9 specimens from Fresno, Selma and Los Banos, 54 (32-74) per cent of greatest width of color of upper parts. Black tip of tail in three males (one subadult and 3 adults) averages 55 (50-60) mm. long. Thus longer than hind foot and averaging 34 per cent of length of tail-vertebrae.

Skull and teeth.--Male (based on 2 adults from Fresno and one from Selma): See measurements and plates 21-23, 30. As described in M. f. nigriauris except that: Weight 3.8 grams; basilar length, 43.7 (43.4-43.9); least width of palate more or less than lateral length of P4; length of tympanic bulla more than length of lower molar and premolar tooth-rows.

Female (no. 2626 W. E. Snyder, from Selma): See measurements and plates 34-36. As described in M. f. nigriauris except that: Weight, 2.5 grams; basilar length, 39.4.

The skull of the female is 34 per cent lighter than the average for the three males.

Compared with skulls of nevadensis from the Sierra Nevada, those of the two adult males from Fresno differ as follows: M1 wider (transversely); tympanic bullae narrower; preorbital part of skull smaller. Comparison with pulchra is made in the account of that subspecies. Compared with skulls of adult males of nigriauris, from Santa Clara County, the two skulls from Fresno are generally smaller and in basilar length, length of tooth-rows and measurements of the teeth fall below the minimum for nigriauris. Relative proportions of the skulls are approximately the same. Comparison with munda reveals essentially the same differences as does comparison with nigriauris except that the difference in size is greater.

Remarks.--The name Mustela xanthogenys Gray was long applied to all the weasels of the interior valleys of California and of the coast of that state south of San Francisco Bay. Gray, when he named the species and when referring to it in later accounts, never defined the locality whence the specimen came more definitely than "California." In 1896, Merriam (1896:25) gave the type locality as "Southern California, probably vicinity of San Diego" and later writers have not contradicted him. The type specimen was obtained in the course of the voyage of the British ship Sulphur, under command of Sir Edward Belcher. Examination of Belcher's (1843, vol. 1, p. 129) narrative of the voyage indicates the following places in California at which the specimen of weasel, described by Gray, could have been obtained: Fort Ross, Bodega, vicinity of San Francisco Bay and up Sacramento River to the mouth of the Feather River, Monterey, Santa Barbara, Buenaventura, San Pedro, San Juan, and San Diego.

Reginald I. Pocock has kindly compared the type specimen in the British Museum with several specimens sent for that purpose. In the first place, comparison of skulls shows that the type specimen is a member of one of the races north of San Diego. In the second place, comparison of skins shows that the inside of the ears are not blackish but similar in color to the back. In fact, Pocock writes under date of February 12, 1929, regarding the type specimen, that "It is practically uniformly colored from the snout to the base of the tail, there being scarcely a trace of the darkening of the head, or muzzle, observable in your specimens [those sent for comparison]." This character of coloration of the ear excludes all the weasels of the Coast region of California from San Francisco Bay southward, namely, M. f. latirostra and M. f. nigriauris. My own examination of this type specimen at a date later than that on which Pocock compared it satisfies me as to the accuracy of his statement above.

Accordingly, the name xanthogenys would seem to apply to one of the two subspecies here called munda and xanthogenys. Perusal of Belcher's narrative of the voyage (loc. cit.) shows that little, if any, opportunity was afforded to obtain vertebrate specimens at Fort Ross or Bodega, both localities within the range of the subspecies here called munda. Furthermore, the type specimen is smaller than individuals of munda from 5 to 6 miles west of Inverness and from Point Arena with which the animals from Fort Ross and Bodega would be expected to agree in size. Weasels from along the north shore of San Francisco Bay are smaller than those on the coast north of the bay. Possibly the type specimen of xanthogenys came from the north side of San Francisco Bay but probably it came from the bank of the Sacramento River and almost certainly not farther up stream from San Francisco Bay than the junction of the Sacramento and Feather rivers. The statement of Belcher (1843, vol. 1, p. 129), regarding the trip up the Sacramento River as far as Point Victoria, lat. 38°46´47" north, and return to San Francisco Bay, that "Cuyote or jackal--fox, racoon, land otter, weasel, and squirrel were obtained" lends strong probability to the idea that this type specimen was taken along the Sacramento River, possibly in the vicinity of the existing city of Sacramento. Unfortunately no specimens are available from the Sacramento Valley. If some were available, a comparison of them and specimens of munda from along the north side of San Francisco Bay and Carquinez Straits with the type specimen of xanthogenys should determine the correct application of the name. For the present it seems best to retain the name munda and apply the name xanthogenys to the weasels inhabiting the northern part of the San Joaquin Valley and presumably the southern part of the Sacramento Valley.

Efforts to obtain specimens of weasels from the Sacramento Valley have been in vain. A juvenal specimen taken five miles south of Fair Oaks, Sacramento County, by Mr. John Fitzgerald, Jr., in December, 1927, was examined at his home and found to agree in coloration with specimens from farther south. Geographically, this specimen probably is more nearly a topotype than any other examined.

Most of the specimens examined are immature and adequate adult cranial material has not been seen. Two adults, one of each sex, from Los Banos have skulls of large size which agree with those of nigriauris. The same is true of one adult and one young female from 4 miles southwest of Turlock, which, unlike the animals from Los Banos, show a darkening of the head extending in reduced degree even to the inside of the ears, as in nigriauris. The slightly darker than average (for xanthogenys) color on the back may indicate intergradation with nevadensis. Intergradation with M. f. nevadensis is shown by specimens, from the southern part of the Sierra Nevada, mentioned in the account of nevadensis.

None of the skulls shows malformation of the frontal sinuses such as result from infestation by parasites.

Specimens examined.--Total number 30, arranged by counties from north to south.

=California.= Sacramento County: Bank of Sacramento River, 1; 5 mi. S Fair Oaks, 1. San Joaquin County: 4 mi. W Stockton, 1. Merced County: Tegner School, 4 mi. SW Turlock, 2; Los Banos, 4 (2, 1 1). Fresno County: Mendota, 1; Biola, 1; Clovis, 1; Fresno, 5 (1, 1, 2, 1); 5 mi. W Fresno, 1; Selma, 3 (2, 1); 4 mi. NW Sanger, 1; 5 mi. S Selma, 1. Tulare County: Monson, 1; 1-1/2 mi. N Goshen, 1; Milo, 1; 2 mi. N Tipton, 1; Poplar, 2. No locality more definite than California, 1.

=Mustela frenata nigriauris= Hall

Long-tailed Weasel

Plates 22, 23, 24, 34, 35, 36 and 41

Mustela frenata nigriauris Hall, Carnegie Instit. Washington Publ. 473:95, November 20, 1936.

Putorius xanthogenys, Baird, Mamm. N. Amer., 1858, p. 176 (part).

Mustela xanthogenys Gray, Ann. and Mag. Nat. Hist., 14(ser. 4):375, 1874 (part?).

Putorius (Gale) brasiliensis frenatus, Coues, Fur-bearing animals, p. 142, 1877 (part).

Putorius xanthogenys xanthogenys, Grinnel, Proc. California Acad. Sciences, fourth series, 3:292, August 28, 1913.

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

Type.--Male, adult, skeleton and skin; no. 32820, Mus. Vert. Zoöl.; Half Moon Bay, San Mateo County, California; received at Museum of Vertebrate Zoölogy, May 4, 1922, through A. L. Hagedoorn, after having been in captivity a few days where death occurred owing to injuries received in trap; original no. 1590.

The skull has each of the zygomatic arches and the anterior end of the nasals broken through. The only part missing is the central two millimeters of the left zygomatic arch. The teeth all are present and entire. The skeleton appears to be complete except for the bones of the feet, which are preserved within the skin. The skin is well made and in good condition.

Range.--Altitudinally, sea level to more than 4000 feet; Sonoran and Transition life-zones of Coast Range and coast of California from San Francisco Bay south to Point Conception, Santa Barbara County, California. See figures 29 and 30 on pages 221 and 314.

Characters for ready recognition.--Differs from M. f. munda, xanthogenys, and pulchra by having inside of ears darker than back rather than same color as back, and from xanthogenys and pulchra in near (l) Antique Brown color of upper parts rather than Buckthorn Brown or near (16 j) Buckthorn Brown to near (h) Yellow Ocher respectively; from M. f. latirostra by postorbital breadth, of adult males and females, less, rather than more, than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite.