Part 34

Compared with the skull of _M. f. longicauda_, that of both sexes averages smaller in every measurement taken. Males of _nevadensis_, on the average, relative to the basilar length, are narrower in the interorbital region and across the zygomata but have the orbitonasal length greater. Stated in another way, the rostrum of _longicauda_ appears to be shorter and broader and the zygomata are more expanded. Females of _nevadensis_, on the average, relative to the basilar length are narrower across the mastoid processes and zygomata and have the braincase deeper at the anterior margin of the basioccipital. Also in _nevadensis_ the mastoid processes do not project so far laterally beyond the braincase, the lambdoidal crest and postorbital processes are less well developed and except in the interparietal region, the temporal ridges hardly meet and they form a sagittal furrow rather than a low sagittal crest which characterizes adult females of _longicauda_. Each of these differences separating the females of _longicauda_ from those of _nevadensis_ are of the same nature, although not necessarily of the same degree, as those which appear in _longicauda_ with increasing age. The differences mentioned above are readily appreciable when series of specimens are compared. However, none of the differences is of great degree, and most parts of the skulls of the two subspecies are of similar relative proportions. Even so, there is but little overlap in actual size. Comparisons with the skulls of _M. f. oribasus_, _alleni_, _neomexicana_, _arizonensis_, _inyoensis_, _pulchra_, _xanthogenys_, _munda_, _saturata_, _oregonensis_, _washingtoni_, _altifrontalis_, and _effera_ are made in the accounts of those subspecies.

_Remarks._--The populations to which the name _nevadensis_ at present is assigned have gone by the name _arizonensis_ since Mearns proposed this name in 1891. Before that time Coues (1877:141) had included individuals of this race under the name _Putorius longicauda_.

Among the populations here assigned to _M. f. nevadensis_, there is some geographic variation but it is of lesser degree than in most other species of mammals which range over the same region. Comparison of 20 adult males from the Rocky Mountains of Colorado with 25 adult males from a place as far distant as the Sierra Nevada of California shows that the two populations closely resemble each other. The specimens from Colorado average a trifle wider across the zygomata, have a longer body and therefore relatively shorter tail, and, except in southern Colorado, a slightly longer hind foot. Comparison of ten adult females from each of the two areas reveals that those from Colorado have a markedly longer hind foot, and a tail somewhat shorter relative to the length of the body. The mentioned differences are the only ones found among the great number of points investigated, except that as remarked by Merriam (1896:23) the Sierran animal has the yellow of the underparts reaching farther up under the chin, the underside of the tail on the average is more suffused with yellowish and the white on the upper lip is more extensive. As regards the last mentioned feature, my check of 34 skins from Colorado reveals that the white extends all the way around the upper lip in every specimen but one, whereas in 69 specimens from the Sierra Nevada the white extends all the way around the upper lip in only 39. However, as further remarked by Merriam (_loc. cit._), not only this but the other color features are inconstant in addition to being slight. When the occurrence of the dark spots near the angles of the mouth are tabulated, it is found that in 33 Colorado-taken specimens they are absent in 19, faintly indicated in 13, and well developed in 1. In 62 California-taken specimens they are absent in 37, faintly indicated in 20, and well developed in 5.

In northwestern Colorado, southern Wyoming, and possibly through the Bear River Divide into southeastern Idaho, long-tailed weasels here referred to _nevadensis_ approach _longicauda_ in large size and occasionally in other features, more closely than do specimens of _nevadensis_ from most other places in its range. This tendency is thought to be significant for much of the area in question lies in or below the Transition Life-zone, the same life zones in which farther to the eastward true _longicauda_ occurs.

One specimen that illustrates this approach to _longicauda_ is an adult male, no. 2334, collection of E. R. Warren, from 6160 feet, Lay, Routt [now Moffat] County, Colorado. In large size and, relative to the basilar length, shorter rostrum and shorter tympanic bullae, it agrees with _longicauda_ but the darker color and, relative to the basilar length, narrowness of the rostrum, interorbital region, zygomatic expanse and the shallowness through the region of the postorbital processes place it with _nevadensis_. Of two other specimens from Steamboat Springs, Routt County, a young male, no. 4010, in the collection of E. R. Warren, has a hind foot (50 mm.) as long as in _longicauda_; and the other, no. 138195, U. S. Nat. Mus., an adult male, agrees well enough in size and proportions with _nevadensis_ but has the coloration typical of _longicauda_.

From Wyoming, one subadult female, no. 177553, U. S. Nat. Mus., from Garrett, is intermediate in size and coloration but is nearer to _nevadensis_ in these particulars, as it is in all other points considered except size of the molar teeth which are as large as in _longicauda_ and larger than in any female _nevadensis_ from Colorado or California. Another female, an adult, no. 179304, U. S. Nat. Mus., from Lonetree, Wyoming, agrees with _longicauda_ in size of skull. Indeed, ten of seventeen cranial measurements exceed the maximum for Colorado-taken _nevadensis_. Where differences exist in relative proportions of the skull as expressed in percentages of the basilar length, the specimen approaches _nevadensis_ in 5 instances and _longicauda_ in only 3. The color is intermediate but much nearer that of _nevadensis_ with which the animal agrees also in external measurements. Ten subadults (5 of each sex) from within 12 miles of Laramie (not Fort Laramie) show greater resemblance to _nevadensis_ but definitely approach _longicauda_. Average external measurements are: [M], 408, 155, 44; [F], 361, 134, 40. The two other specimens examined from this general locality, a young female, no. 2711, Mus. Vert. Zoöl., from Fort Bridger, and a subadult female, no. 188377, U. S. Nat. Mus., from Bridger Pass, show no departures from _nevadensis_ of similar age.

The specimens from scattered localities in the Transition Life-zone of northwestern Colorado and southern Wyoming are larger than _nevadensis_ is elsewhere, and also in certain other features resemble _longicauda_ of the plains to the eastward. Everything considered, the animals in question are much more like _nevadensis_ than _longicauda_. Study of more specimens, especially from Wyoming, might provide grounds for recognizing as a different subspecies the animals in this large area comprising parts of Colorado and Wyoming from which so few specimens now are available. Possibly the name _Putorius culbertsoni_ Coues would apply. Decision on that point will require adequate material from the type locality, Fort Laramie. See discussion of this name under _M. f. longicauda_.

In southeastern Idaho males are larger than they are at most other places within the range of _nevadensis_. An average of 7 adults and subadults from Pegram, Montpelier, Springfield, and the vicinity of Pocatello, reveals, when compared with the average of _nevadensis_ from Colorado and that of _longicauda_ from the Great Plains, that this population from southeastern Idaho is nearest to _longicauda_ in linear measurements of the orbitonasal length, mastoid breadth, length of tympanic bullae, and as expressed in percentage of the basilar length, length of tooth-row, breadth of rostrum, and zygomatic breadth. In all other points of size, relative proportions and color, the animals approach nearer to, or actually agree with, _nevadensis_.

The specimens commented upon clearly show intergradation between _nevadensis_ and _longicauda_. Similarly, the specimens from Scottsbluff County, Nebraska, here referred to _M. f. alleni_, by their larger size suggest intergradation of that subspecies with the larger _nevadensis-longicauda_ stock although the approach is more toward _longicauda_ than _nevadensis_. Between _oribasus_ and _nevadensis_, however, there is no lack of material showing intergradation. As set forth in the account of _oribasus_, specimens from Montana are truly intermediate structurally as well as geographically.

Intergradation with _washingtoni_ is shown by specimens from the northern part of the Cascade Range in Chelan and Okanogan counties, Washington. The adult male, U. S. Nat. Mus., no. 235183, from Bald Mountain, is referable to _washingtoni_ on the basis of cranial characters but all the other adult and subadult specimens examined from Chelan and Okanogan counties are nearer _nevadensis_ on the basis of cranial characters. Indeed, some show no approach to _washingtoni_ in cranial characters. As might be expected on geographic grounds, the specimen from Easton, U. S. Nat. Mus., male subadult, no. 116870, shows approach to _washingtoni_. This is true of the coloration of the hind limbs, small size of the tympanic bullae, and relatively greater length of the preorbital part of the skull. However, the greater width of the light color of the underparts and relatively great breadth across the mastoid processes and zygomatic arches are points of agreement with _nevadensis_. Similarly, a series of 7 specimens from the Entait River, 20 miles above its mouth, in tone of color is nearer to _washingtoni_, as is one of the two skulls of adult males in length of the preorbital region. However, in greater breadth of the skull otherwise, and in the relatively great width of the light color of the underparts, the animals are nearer to _nevadensis_, to which they are here referred. Some of these characters mentioned above in which departure is shown from typical _nevadensis_ are characters that show approach to _altifrontalis_. This is especially true of the more intense coloration and restriction of the color of the underparts.

Complete intergradation with _effera_ is shown by specimens from southern Oregon. The change from small _effera_ to the larger _nevadensis_ here is gradual; consequently in northeastern California and southern Oregon the size increases gradually to the northward. Specimens showing complete intergradation with _oregonensis_ and _saturata_ are wanting. However, one specimen from Crescent Lake suggests _oregonensis_ in having near (18) apricot yellow underparts such as occur frequently in _oregonensis_. Also some specimens from northern California approach _saturata_ in having the color of the underparts reduced in the extent to which it reaches out on the under side of the tail. This fact and the consideration that the two races are less different from one another than are other kinds which definitely are known to intergrade leave no doubt but that material from the intervening localities would show complete intergradation.

Intergradation between _nevadensis_ and _munda_ is indicated by specimens from South Yolla Bolly Mountain, Trinity County, which are commented on at greater length in the account of _M. f. munda_. _M. f. inyoensis_ is so closely related to _nevadensis_ as to leave no doubt that specimens from suitable localities will show actual intergradation. That intergradation occurs directly with the bridled weasel of the interior valleys of California, _M. f. xanthogenys_, is shown by specimens from along the west-facing flank of the southern part of the Sierra Nevada. Probably intergradation occurs all along the Sierra Nevada on the western slope but specimens are lacking to show this. Weasels are known to occur in the foothill territory and the lesser attention given to this region by mammal collectors than to the higher parts of the mountains may explain the lack of preserved specimens. Individual specimens, here referred to _nevadensis_, but, showing varying degrees of approach to _xanthogenys_ are as follows: A female from Hume; a male and a female from 8000 feet elevation, Monache Meadows; a male from 9800 feet elevation on the east fork of the Kaweah River; and 7 specimens, probably one family, from one-half mile south of Mineral King, 7850 feet. Of the specimens from 7850 feet, the adult male has no light facial markings and the head is only slightly darker than the back. The adult female has much restricted, light facial markings and the intervening areas are darker than in the male. The five juveniles trapped in the same burrow as the female, each has more extensive light facial markings than the adult female although the area of this varies from only slightly more than in the female to as much as in typical specimens of _xanthogenys_. Also, the dark color of the head in these five specimens averages darker than in _nevadensis_ and more as in weasels to the southwestward especially _latirostra_. One of the five juveniles is lighter colored over all of the upper parts than _nevadensis_ and is suggestive of _xanthogenys_ in this respect. Finally, the adult male has on the underparts small spots of ochraceous orange suggestive of _latirostra_ and some individuals of _pulchra_. No. 30655/42628, U. S. Nat. Mus., taken on Mount Whitney, also shows white facial markings and some other features of the valley-inhabiting _xanthogenys_. A suggestion of intergradation with _arizonensis_ is furnished by specimens, referred to that race, from Springerville and the Kaibab Plateau. No specimens happen to be available from the region in which intergradation would be expected between _nevadensis_ and _neomexicana_. Since _neomexicana_ and _arizonensis_ intergrade it is probable that _nevadensis_ also will be found to intergrade with _neomexicana_. In summary, _nevadensis_ is judged to intergrade with each of the subspecies of _Mustela frenata_ whose range adjoins that of _nevadensis_.

This subspecies is remarkably free from injury to the frontal sinuses such as result from the presence of parasites. In 98 adults from Oregon, California, Nevada, and Colorado, no malformation was noted. Only 1 of the 26 specimens from Washington was malformed and it was an intergrade with _washingtoni_. The single adult from New Mexico was diseased, as were 3 of the 6 from British Columbia, 1 of the 20 from Idaho, and 1 of the 7 from Utah.

_Specimens examined._--Total number, 568, arranged alphabetically by provinces and states and from north to south by counties in each state. Unless otherwise indicated specimens are in the collection of the United States National Museum.

=Arizona.= _Apache County_: 15 mi. E Luka Chu Kai Navajo School, 8000 ft., 2.

=British Columbia.= Monte Cr., 20 mi. E Kamloops, 1[21]; Sicamous, 2; Okanagan, 18 (7[2], 6[85], 1[75], 1[86]); Monashee Pass, 1[31]; Swan Lake, near Okanagan Landing, 1[22]; Okanagan Landing, 11 (2[74], 3[31], 3[86], 3[22]); Vernon, 1[74]; Hope-Princeton Summit, 5600 ft., 1[77]; Hope, 1[20]; Similkameen, 1[77]; Osoyoos-Bridesville Summit, 1[77]; Anarchist Mt., Osoyoos, 1[31]; Myer's Creek, 1[77]; Rossland, Mt. Glory, 7000 ft, 1[77]; Cascade, 1[77]; Nelson, 1.

=California.= _Siskiyou County_: Hornbrook, 1; Tule Lake Refuge, 5[74]; Upper Mud Creek, 6700 ft., Mt. Shasta, 3; Mt. Shasta, 1. _Modoc County_: Goose Lake, 1[20]; Joseph Creek, 1[74]; 5280 ft., Parker Creek, near Alturas, 1[74]; Warner Mts., near Alturas, 1[8]; 5 mi. NW Eagle Peak, 7000 ft., 2[74]; Shields Creek, 5000 ft., 1[74]; Jess Valley, 1[8]. _Shasta County_: Cassel, 1. _Lassen County_: 3 mi. W Eagle Lake, 5800 ft., 1[74]; 4 mi. S Eagle Lake, 6000 ft., 2[74]; Mill Creek, 5000 ft., S base Mt. Lassen, 1; 6 mi. SW Calneva, 1. _Tehama County_: Dale's, 600 ft., on Paines Creek, 1[74]. _Plumas County_: Kelly's, 2 mi. S Willow Lake, 5200 ft., 3[74]; Quincy, 4[68]; Beckwith, Sierra Valley, 1. _Butte County_: Jonesville, 1[74]. _Sierra_ _County_: Little Truckee River, 6500 ft., 3 mi. N Independence Lake, 2[42]. _Nevada County_: Independence Lake, 1[74]. _Placer County_: Donner, 3; 2 mi. W Soda Springs Station, 6500 ft., 1[74]; Blue Canyon, 5000 ft., 2 (1[74]); 4 mi. S Tahoe City, 1[74]. _Eldorado County_: 5 mi. S Tallac, 6300 ft., 1; Gilmore Lake, Mt. Tallac, 2[74]; Mt. Tallac, 1[68]; Phillips, 1[59]. _Alpine County_: 8000 ft., Hope Valley, 1; 8000 ft., Silver Creek, 1. _Tuolumne County_: Strawberry, 5200 ft., 1[74]; 9300 ft., Ten Lakes, Yosemite Park, 1[74]; Tuolumne Meadows, 8600 ft., Yosemite Park, 1[74]; Tuolumne Meadows (Soda Springs), 1; Tuolumne Meadows, 8500 ft., Yosemite Park, 1[74]; Sequoia, 1. _Mariposa County_: Chinquapin, 6256 ft., 2[74]; Merced Grove Big Trees, 5400 ft., 1[74]; Wawona, 1; no locality more definite than county, 1. _Madera County_: Bass Lake, 1[74]. _Mono County_: Tioga Crest, near Tioga Pass, 4[74]; Warren Creek, 1[74]; Tioga Lake, 1[74]; Ellery Lake, 9600 ft., 1[74]; Mono Lake P. O., Mono Lake, 1[74]; Walker Lake, 8000 ft., 2[74]; Pine City, 1; Mammoth, 13 (12[59], 1[14]); 10300 ft., near Big Prospector Meadow, White Mts., 2[74]. _Inyo County_: Little Onion Valley, 7500 ft., 1[74]; N Fork Bishop Cr., 10500 ft., 1[74]; S fork Bishop Cr., Andrews Camp, 8000 ft., 1[74]; South Lake, S Fk. Bishop Cr., 9750 ft., 1[74]; Lamarck Cr., 9900 ft., 15 mi. SW Bishop, 1[74]. _Fresno County_: Hume, 1. _Tulare County_: Mt. Whitney, 2; Whitney Meadow, 9800 ft., 1[74]; Monache Meadow, 8000 ft., 3[74]; E fork Kaweah River, 9800 ft., 1; 1/2 mi. S Mineral King, 7850 ft., 7[52]; Quaking Aspen Meadow, 7500 ft., 1[52].

=Colorado.= _Moffat County_: Lay, 1[19]. _Routt County_: Steamboat Springs, 2 (1[19]); no locality more definite than county, 1[57]. _Jackson County_: Higho, North Park, 8400 ft., 1; Buffalo or Illinois Creek, "near Rand," 6[74]. _Washington County_: 6 mi. NE Hillrose, 1[74]. _Larimer County_: Estes Park, 2 (1[2], 1[7]); Pinewood, 1; Loveland, 2 (1[57]); no locality more definite than county, 1[7]. _Rio Blanco County_: Compass Creek, 9000 ft., 1[2]; White River, 6200 ft., 1[21]; Piceance Creek, 6200 ft., 1[2]; Dry Fork, 6200-6600 ft., 4[2]; Meeker, 1; Marvine, 1[74]. _Grand County_: Crembling [= Kremmling?], 1[50]; Middle Park, 1[57]. _Boulder County_: Foot Mt. Meeker, 8700 ft., 1[2]; Silver Lake Mine, 1[60]; Boulder, 1[60]; Dixie Lake, 2 (1[2], 1[57]); Caribou, 1[2]; no locality more definite than county, 1. _Clear Creek County_?: Grays Peak, 1[93]. _Jefferson County_: 7000 ft., Mt. Parks, 1[57]; 6 mi. W Denver, 1[57]. _Adams County_: Barr, 1[2]; near East Lake, 2[57]. _Denver County_: Denver, 2 (1[2], 1[74]). _Arapahoe County_: Littleton, 1[19]. _Summit County_: Breckenridge, 1[57]. _Eagle County_: Eagle, 9500 ft., 1[104]. _Park County_: Jefferson, 4 (1[2]); 12800 ft., Mt. Bross, 1[57]. _Mesa County_: Tunnel, 1. _Montrose County_: near Crawford, Clear Fork of Smiths Fork, 1[19]; Coventry, 3 (1[19]); Naturita, 1; Paradox, 1[94]; West Paradox Valley, 1[57]. _Pitkin County_: Placita, 2[26]. _Gunnison County_: Marble, 1[26], Crested Butte, 2[19]; Deckers Ranch, Crested Butte, 2[19]; Sapinero, 7245 ft., 1[19]. _Chaffee County_: Buena Vista, 1[76]; Hancock, 1[16]; Salida, 5[19]. _Teller County_: Glencore, Pikes Peak, 1[76]. _El Paso County_: Monument, 1[76]; Seven Lakes, 1[19]; Lake Moraine, 10250 ft., 1[19]; Colorado Springs, 6000 ft., 1[19]; 5 mi. E Sand Creek, Colorado Springs, 1[19]; no locality more definite than county, 1[50]. _Saguache County_: Villa Grove, 1[19]; Pierce Place, Cochetopa Nat. Forest, 1; Houselog Creek, Cochetopa Nat. Forest, 1; P. Tevebaugh's Ranch, near Cochetopa Pass, 1; P. Tevebaugh's Ranch, 9 mi. S Cochetopa Pass, 1. _Rio Grande County_: between Monte Vista and Del Norte, 1[88]. _Archuleta County_: Upper Navajo River, 2[57]; Navajo River, 5 (4[57], 1[2]); Chromo, 2[57]. _Conejos County_: Osier, 3[57]. _Montezuma County_: Ure Peak, 1[57]. _County_ in question: Del Norte Peak, 1[76]; no locality more definite than state, 4[75].

=Idaho.= _Latah County_: Cedar Mt., 4000 ft., 12 mi. NE Moscow, 1[55]; Moscow and 1/2 mi. W, 2[97]. _Idaho County_: Lochsa River (= Locksaw Fork), 1; between Selway Riv., and S Fork Clearwater Riv., 8[74]; Selway Divide, 8[74]; Pilot Creek, 2[74]; Newsome Cr., 1[74]. _Lemhi County_: Salmon River Mts., (now Lemhi Mts.), 8000 ft., 5; Leadore, 3. _Adams County_: summit Smith Mt., 7500 ft., 1[41]. _Washington County_: Midvale, 2. _Custer County_: Pahsimeroi Mts., 1; Double Springs, 16 mi. NE Dickey, 1[74]; Mackay?, 1; Stanley Lake, 1. _Payette County_: 2 mi. S Payette, 1[74]. _Fremont County_: 17 mi. E, 4 mi. N Ashton, 6275 ft., 2[74]. _Teton County_: 3 mi. S Victor, 1[74]. _Jefferson County_: 20 mi. W Camas, 1. _Blaine County_: Sawtooth City, 1; Ketchum, 5 (3[50], 2[75]). _Canyon County_: Nampa 3. _Clark County_: Dry Creek, Targhee Nat. Forest, 1[2]; Birch Creek, 2. _County_ in question: North fork of Teton River, 1. _Bingham County_: Shelley, 1; Alridge, 2; Springfield, 1. _Lincoln County_: Shoshone, 1. _Minidoka County_: 1/4 mi. E Heyburn Bridge, 1[74]. _Power County_: 4 mi. NW American Falls, 1[74]. _Bannock County_: 3 mi. N Schutt's Mine, Ross Creek, 1[74]; 3 mi. N Pocatello, 1[74]; near (within 10 miles of) Pocatello, 1[74]; 3 mi. S Pocatello, 1[74]; 1 mi. E Portneuf, 1[74]; 2 mi. up Mink Creek, 2 (1[74], 1[41]); Inkom, 2; Swan Lake, 1. _Owyhee County_: 5 mi. SE Riddle, 1; Three Creek, 2. _Cassia County_: Elba, 1[52]. _Bear Lake County_: Geneva, 6171 ft., 1[74]; Montpelier, 1; Paris, 6000 ft., 1[6]; Pegram, 2.

=Nevada.= _Humboldt County_: Alder Creek, 7000 ft., Pine Forest Mts., 1[74]; head of Big Creek, 8000 ft., Pine Forest Mts., 1[74]; Cottonwood Range, 1; Calico Mt., Little Owyhee R., 1; Mahogany, Little Owyhee R., 2; Sulphur, 1. _Pershing County_: Lovelocks, 1. _Elko County_: Mountain City, 3; Three Lakes, Ruby Mts., 1[41]. _Washoe County_: Pyramid Lake, 1; 3 mi. E Reno, 1[74]; Incline Creek, 7100 ft., 1[74]; 2-1/2 mi. S Incline, 6250 ft., 1[74]; E side Marlette Lake, 8000 ft., 1[74]; Marlette Lake, 8000 ft., 1[74]. _Ormsby County_: 1/2 mi. S Marlette Lake, 8150 ft., 1[74]. _Churchill County_: 4 mi. W Fallon, 1[74]; 3 mi. W Fallon, 1[74]; 2 mi. W Fallon, 1[74]; Fallon, 3970 ft., 1[74]. 5 mi. S Fallon, 4000 ft., 1[74]; 8 mi. S and 3 mi. E Fallon, 1[74]. _Douglas County_: Mt. Siegel, 1[60]. _Mineral County_: Lapon Cañon, 8900 ft., Mt. Grant, 1. _Nye County_: Arc Dome, 1; 10700 ft., 1/2 mi. SW Jefferson Peak, Toquima Range, 1[74]. _White Pine County_: 3 mi. E Baker, 1[74]; Baker Creek, 6600 ft., 4[74]; Baker Creek, 8400 to 8450 ft., 4[74]; Gleason Creek, 7500 ft., 1[74]. _Esmeralda County_: Arlemont, 4850 ft., Fish Lake Valley, 1[74]. _Lincoln County_: 3 mi. S Crystal Spring, 3900 ft., Pahranagat Valley, 1[27].

=New Mexico.= _Taos County_: 2 mi. N Twining, 10500 ft., 1; Taos, 2. _Santa Fe County_: 11600 ft., Pecos Baldy, 1. _San Miguel County_: 8000 ft., above Willis, Pecos River, Forest Reserve, 2[75]; Ribera, 1.