Chapter XV: Introduction (14)

_Color._--Winter pelage unknown; probably white except, of course,
tip of tail. Summer pelage as described in _Mustela frenata
longicauda_ except that: Least width of color of underparts
averaging, in 3 males from Black Hills, 54 (38-62) per cent of
greatest width of color of upper parts. Black tip of tail
averaging 43 (40-45) mm. long. Thus, averaging approximately same
length as hind foot and in type specimen amounting to 33 per cent
of length of tail-vertebrae.

_Skull and teeth._--Male (based on the type and no. 7440 Amer.
Mus. Nat. Hist., from Hill City, S. Dak.): See measurements and
plates 18-20. As described in _Mustela frenata longicauda_ except
that: Weight, 3.1 (3.0-3.2) grams; basilar length, 41.0
(40.9-41.0); mastoid breadth not less than postpalatal length;
breadth of rostrum more than length of P4; anterior margin of
tympanic bulla as far posterior to foramen ovale as width of 4 to
5 upper incisors; height of tympanic bulla more or less than
distance from its anterior margin to foramen ovale.

Female (based on no. 7441, American Mus. Nat. Hist., from Black
Hills, S. Dak.): See measurements and plates 31-33. As described
in _Mustela frenata longicauda_ except that: Weight, 2.0 grams;
basilar length 37.6. The skull of the female is 35 per cent
lighter than the average for the two males.

Comparison with _M. f. longicauda_ and _M. f. nevadensis_ reveals
that the tympanic bullae average more nearly flat and that the
skull is smaller.

_Remarks._--Animals of this subspecies were described and named by Merriam in 1896 as a distinct species on the basis of two or possibly three specimens from the Black Hills of South Dakota and the name seems never to have been applied to specimens from other regions. Vernon Bailey obtained only the one specimen, the type, on his trip in 1888, but two more were obtained for the American Museum of Natural History by Walter Granger in 1894.

_Mustela frenata alleni_ combines the light coloration of _M. f. longicauda_ with the small size of _M. f. nevadensis_. Indeed, the size may average less than that of _nevadensis_. _M. f. alleni_ seems to reach its extreme of small size in the Black Hills of South Dakota. Specimens from Mitchell, Scottsbluff County, Nebraska, here referred to alleni are of larger size and in this respect are intermediate between the subspecies _alleni_ and _longicauda_. Of the two specimens available from Chadron, Nebraska, and here referred to as _longicauda_, the female, M1 #6, is almost exactly intermediate in size between _alleni_ and _longicauda_, whereas the male, Ml #11, is as large as the average-sized _longicauda_.

None of the nine skulls (5 adults) shows malformation resulting from the infestation of the frontal sinuses with parasites.

_Specimens examined._--Total number, 10, as follows.

=Wyoming.= _Crook County_: Sundance, 1[91].

=South Dakota.= _Pennington County_: Hill City, 1[2]; 20 mi. N Elk
Mt, 1[91]. _County_ in question: Black Hills, 1[2]. _Custer
County_: Custer, 2 (1[91], 1[2]).

=Nebraska.= _Scottsbluff County_: Mitchell, 4[35].

=Mustela frenata arizonensis= (Mearns)

Long-tailed Weasel

Plates 19, 20, 21, 31, 32 and 33

_Putorius arizonensis_ Mearns, Bull. Amer. Mus. Nat. Hist., 3:234,
June, 1891; Merriam, N. Amer. Fauna, 11:22, fig. 12, June 30,
1896.

_Mustela arizonensis_, Miller, U. S. Nat. Mus. Bull., 79:99,
December 31, 1912.

_Mustela frenata arizonensis_, Hall, Carnegie Instit. Washington
Publ. 473:106, November 20, 1936.

_Type._--Female, adult, skull and skin; no. 2490/1886, Amer. Mus.
Nat. Hist.; San Francisco Forest [then (1886?), Yavapai County],
Arizona; June 20, 1886; obtained by Edgar A. Mearns.

The skull (plates 31-33) is complete and unbroken save for a small
puncture in the right squamosal. The incisors above and below and
M^2 and P^2 on each side are missing. Four canines are preserved
separately. Otherwise the teeth are in place. The skin has been
taken down from a mount. Some hair has been lost from in front of
the ears. Seven mammae are evident and show the animal to have
been nursing young. The slightly faded color was mentioned by
Mearns in the original description. He says (1891:234): "The
memorandum of the colors was made before skinning, the specimen
having been subsequently preserved in a solution of alum and salt,
which extracted much of the coloring matter."

_Range._--Transition to Hudsonian life-zones of Arizona and
extreme western New Mexico, along the Colorado River, and south of
the Little Colorado River, from San Francisco Mountain region
along Mogollon Plateau to extreme western New Mexico. See figure
29 on page 221.

_Characters for ready recognition._--Differs from _M. f.
neomexicana_ by near (14 _n_) Brussels Brown rather than Buckthorn
Brown color of upper parts, in absence rather than presence of
white frontal spot continuous with color of underparts, in basilar
length of less than 44 in males and 39.3 in females; from _M. f.
nevadensis_ in that total length averages less than 375 in males
and 330 in females, basilar length averaging less than 41 in males
and less than 36.7 in females.

_Description._--_Size._--Male: No. 24679/32071, from
Springerville, and no. 248993 from the Kaibab Plateau, measure
respectively, as follows: Total length, 363, 367; length of tail,
140, 143; length of hind foot, 41.5, 41.0. Tail is 63, and 64 per
cent as long as head and body. These males, the only specimens of
that sex of which external measurements are available, probably
are grading toward _nevadensis_ and therefore are nontypical.

Female: Three specimens, one young from Little Spring, a subadult
from Deadmans Flat and the type specimen, measure respectively as
follows: Total length, 323, 296, 302; length of tail, 110, 101,
109; length of hind foot, 38, 33, 36. These average, 307, 107, 36.
Tail averages 53 per cent as long as head and body.

Differences in external measurements of the two sexes are: Total
length, 56; length of tail, 39; hind foot, 5.5.

_Externals._--Longest facial vibrissae black, brown or white
(often all three colors in same specimen) and extending beyond
ear; carpal vibrissae same color as underparts and extending to
apical pad of fifth digit; hairiness of foot soles (in summer
pelage) about as shown in figure 19.

_Color._--Winter pelage unknown. Summer pelage with upper parts
near (14 n) Brussels Brown or tone 2 of Raw Umber of Oberthür and
Dauthenay, Pl. 301, darker on top of head from nose to line
connecting posterior margins of ears. Tip of tail always black.
Chin and upper lips white. Remainder of underparts Buff Yellow to
Straw Yellow and rarely Ochraceous 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 legs
to ankles and over antiplantar faces of toes, medial third of
tarsus, and over proximal fifth to fourth of ventral side of tail.
Least width of color of underparts averaging, in 8 specimens, 44
(29-54) per cent of greatest width of color of upper parts. Black
tip of tail, in four females averaging 35 (33-38) mm. long. Thus,
averaging shorter than hind foot and 32 per cent of length of
tail-vertebrae. Three of the eight specimens before me (no. 242671
from 25 mi. SE Flagstaff, not available at time of this
accounting) have the dark spot near the angle of the mouth faintly
indicated, whereas the other five lack the spots. The color is as
in _M. f. nevadensis_.

_Skull and teeth._--Male (based on 55211, 65231, and 248993; see
p. 422): See measurements and plates 19-21; weight 2.7 and 3.1
grams; basilar length, 40.4; zygomatic breadth more than distance
between condylar foramen and Ml 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 and more than width of basioccipital measured
from medial margin of one foramen lacerum posterior to its
opposite; interorbital breadth more or less than distance between
foramen opticum and anterior margin of tympanic bulla; breadth of
rostrum less than length of tympanic bulla; least width of palate
more or less than medial length of P4; anterior margin of tympanic
bulla as far posterior to foramen ovale as width of 3-1/2
(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-premolar tooth-row
and longer or shorter than rostrum; anterior margin of masseteric
fossa below talonid of m1.

Female (based on the type specimen): See measurements and plates
31-33; weight, 1.6 grams; basilar length, 35.5; zygomatic breadth
less than distance between condylar foramen and M1 and more than
distance between anterior palatine foramen and anterior margin of
tympanic bulla (nearly equal in each instance); postorbital
breadth less than length of upper premolars and greater (7.1-8.4)
than width of basioccipital measured from medial margin of one
foramen lacerum posterior to its opposite; least width of palate
equal to inside 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-premolar tooth-row and greater than length of rostrum.

The skull of the female averages 41 per cent lighter than that of
the male.

Compared with the skull of _M. f. nevadensis_, that of _arizonensis_ is smaller, less heavily ridged and has more inflated tympanic bullae and a relatively greater mastoid breadth. Comparison with the skull of _M. f. neomexicana_ is made in the account of that subspecies.

_Remarks._--In 1891 Mearns (234-235) named this weasel as a full species on the basis of two individuals taken by him in 1886 and 1887. Since that time only a few additional specimens have been preserved. Only four are adults. Although this material does not permit of a definition of the subspecies as precise as could be wished, still, it clearly shows that the animals from the plateau region of Arizona are recognizably different from those farther north in the Sierra Nevada of California and those of the Rocky Mountains and Great Basin region northward to the Canadian border. These more northern animals have gone by Mearns' name, _arizonensis_, since the date of its proposal until 1939 when the name _nevadensis_ was proposed.

The smaller size, especially of the skull, and the greater inflation of the tympanic bullae are the outstanding characters which distinguish _arizonensis_ from the similarly marked _nevadensis_. The bullae are relatively much inflated throughout but especially so on the posteromedial parts.

Although the three adult males and two subadult females available of this subspecies are smaller in most parts measured than any of the scores of _nevadensis_ of similar age that have been measured, overlap in size probably will be found as additional specimens of _arizonensis_ become available. A young female, no. 18513, coll. D. R. Dickey, from Little Spring, does have certain cranial measurements as large as are found in the minimum-sized _nevadensis_ from farther north.

Intergradation with the two subspecies whose geographic ranges adjoin that of _arizonensis_ is indicated by specimens at hand. One of these is the adult male from 25 miles southeast of Flagstaff, which shows decided approach to _neomexicana_, in color and in possessing white facial markings less well developed than in _neomexicana_. Even better developed white facial markings, with intervening blackish coloration, are displayed by no. 148271, U. S. Nat. Mus., from 8500 feet altitude on Willow Creek, New Mexico. This subadult female shows approach to _neomexicana_ also in larger size of the skull and entire animal. The great inflation of the posterior part of each of its bullae and the dark color of the upper parts are characters of _arizonensis_. The color of the underparts stops at the ankles leaving the hind feet dark colored, in which respect the specimen is unlike either _neomexicana_ or _arizonensis_. If additional specimens showing the same characters as this one be found at other nearby localities they probably should be given recognition as a separate subspecies. For the present it seems best to regard the specimen merely as an intergrade. Although it might, with almost equal propriety, be referred to either _neomexicana_ or _arizonensis_, the specimen is here placed with the latter. The subadult male from Springerville, Arizona, is of larger size than the topotypical male of _arizonensis_ and in this respect shows slight approach to _nevadensis_. The narrower mastoidal breadth and slightly less inflated tympanic bullae of the male from the Kaibab Plateau may reflect merely individual variation or may represent intergradation in these features with _nevadensis_.

The statement made by Merriam (1896:22) that, "The type specimen . . . is an immature female and is of unusually small size. A male obtained by him [Mearns] near the same place is of the normal size, as is another male in the Department collection from Springerville, Ariz., collected by E. W. Nelson," needs correction. The female is not immature. The specimen obtained by Mearns near the same place probably refers to Amer. Mus. No. 2489, from Quaking Asp Settlement, which lacks both the skull and external measurements. As stuffed it is of small size for a male. The male from Springerville, as shown by the external and cranial measurements, is not of normal (_i. e._ average) size, but is smaller than the average for the other populations of similarly colored weasels referred to by Merriam (_op. cit._) as _arizonensis_ but here described under the name _nevadensis_.

None of the skulls shows signs of infestation of the frontal sinuses by parasites.

_Specimens examined._--Total number, 17, arranged alphabetically
by 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.= _Coconino County_: VT Park, Kaibab Plateau, 1; Deadman
Flat, 6400 ft., 1[74]; Little Spring, 1[59]; Government Prairie,
near Parks, 1[74]; _Coconino? County_: San Francisco Forest
(Yavapai Co., in 1886), 1[2]; 25 mi. SE Flagstaff, 1; Quaking Asp
Settlement, 1[2]. _Apache County_: Springerville, 1; North Fork
White River, White Mts., 8200 ft., 4[87]; head San Francisco
River, Judd Ranch, Alpine, 1[74]; 2 mi. SE Big Lake Knoll, 8700
ft., 24 mi. S Springerville, 1[74]. _Greenlee County_: S end Blue
Range, 9000 ft., Prieto Plateau, 1; Beaver Creek, 7000 ft., 1[74].

=New Mexico.= _Grant County_: Mogollon Mts., Willow Creek, 8500
ft., 1.

=Mustela frenata nevadensis= Hall

Long-tailed Weasel

Plates 19, 20, 21, 33, 34, 35 and 39

_Mustela frenata nevadensis_ Hall, Carnegie Instit. Washington
Publ. 473:91, November 20, 1936.

_Putorius longicauda_, Coues, Fur-bearing animals, p. 136, 1877
(part); Merriam, N. Amer. Fauna, 5:83, July 30, 1891.

_Putorius (Gale) brasiliensis frenatus_, Coues, Fur-bearing
animals, p. 142, 1877 (part).

_Putorius arizonensis_, Merriam, N. Amer. Fauna, 11:22, figs. 13,
14, June 30, 1896 (part); Stephens, Mammals of California, p.
247, 1906.

_Mustela arizonensis_, Grinnell and Swarth, Univ. California Publ.
Zoöl., 10:376, October 31, 1913; Whitlow and Hall, Univ.
California Publ. Zoöl., 40:247, September 30, 1933.

_Mustela arizonensis arizonensis_, Grinnell, Univ. California Publ.
Zoöl., 40:102, September 26, 1933.

_Mustela frenata_, Boyer, Journ. Mamm., 24:99, February 20, 1943.

_Type._--Female, adult, skull and skin; no. 41053, Mus. Vert.
Zoöl.; three miles east Baker, White Pine County, Nevada; May 30,
1929; obtained by E. R. Hall and W. C. Russell; original no. 2674,
E. R. H.

The skull (plates 33-35) is complete and unbroken. The teeth all
are present and entire. The skin is fairly well made. Eight mammae
are evident and show the animal to have been nursing young.

_Range._--Altitudinally, 700 feet at Wenatchee, Washington, to the
highest parts of the mountains of the western United States; Upper
Sonoran Life-zone to Arctic Alpine Life-zone; southern British
Columbia in the Cascades and territory west to Monashee Mountains,
and Nelson, southward in the Cascades of northern Washington, over
western Washington, Idaho, Utah, and Nevada to northeastern
Arizona and northern New Mexico; westward from the eastern base of
the Rocky Mountains in Colorado to the western base of the Sierra
Nevada and Cascades of California and to the Cascades of southern
Oregon. See figures 29 and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f. oribasus_
by smaller average size, see measurements; from _M. f. longicauda_
by near (14 _n_ to _l_) Brussels Brown rather than near (_h_) Clay
Color of the upper parts, and in males by a shallower occiput in
which the depth of the skull, exclusive of the sagittal crest, and
taken at the anterior border of the basioccipital, amounts to
less than 59 per cent of the mastoid breadth; from _M. f. alleni_
by near (14 _n_ to _l_) Brussels Brown rather than near (_h_) Clay
Color of upper parts in summer; from _M. f. neomexicana_ by near
(14 _n_ to _l_) Brussels Brown rather than Buckthorn Brown color
of upper parts, in absence of white frontal spot continuous with
color of underparts, in basilar length of less than 46 in males
and 40 in females; from _M. f. arizonensis_ by total length
averaging more than 375 in males and 330 in females, basilar
length averaging more than 41 in males and 36.7 in females; from
_M. f. inyoensis_ by absence of white facial markings; from _M. f.
pulchra_ by absence of light facial markings, near (14 _n_ to _l_)
Brussels Brown rather than near (16 _j_) Buckthorn Brown color of
upper parts, and lesser size, hind foot less than 40 in females
and basilar length averaging less than 46.0 in males; from _M. f.
xanthogenys_ by absence of light facial markings and near (14 _n_
to _l_) Brussels Brown rather than Buckthorn Brown color of upper
parts; from _M. f. munda_ by absence of white facial markings,
presence of color of underparts on ventral face of proximal third
of tail, and hind foot of less than 50 in males; from _M. f.
saturata_ by presence of light color of underparts on tail and
ankle and in lesser average breadth across mastoid processes of
skull (see measurements); from _M. f. oregonensis_ by absence of
nasofrontal white patch, presence of light color of underparts on
ventral face of tail, and shorter skull, which, relative to its
length in males, is deeper through the braincase; from _M. f.
washingtoni_ by presence of light color of underparts on ventral
face of tail, by skull which in male relative to basilar length is
shorter in the preorbital region and wider across the zygomata and
mastoid processes, and in female has longer preorbital region and
larger bullae (see measurements); from _M. f. altifrontalis_ by
lighter colored upper parts which are tones 1 to 3 of Raw Umber,
pl. 301, rather than tone 4 of Brownish Drab, pl. 302, of Oberthür
and Dauthenay, by Buff-Yellow to Straw Yellow rather than near
(14´ _a_ to 16´ _c_) Ochraceous-Buff color of underparts, by least
width of color of underparts amounting to more than 37 per cent of
greatest width of color of upper parts, by presence of color of
underparts on ventral side of tail and on hind leg over ankle, and
by lesser depth of skull through frontal region; from _M. f.
effera_ by larger size, males averaging 12-1/2 per cent larger in
external measurements, 8 per cent larger in linear measurements of
skull, and 22 per cent heavier in weight of skull, total length
averaging 400 rather than 360, basilar length averaging 43.6
rather than 40.5.

_Description._--_Size._--Male: Twenty-one adults from the southern
half of the Sierra Nevada of California yield average and extreme
measurements as follows: Total length, 400 (356-428); length of
tail, 150 (125-178); length of hind foot, 46.1 (42-50). Tail
averages 60 per cent as long as head and body. Length of hind foot
averaging more than basal length. Corresponding measurements of
twelve adults from extreme southern and southwestern Colorado are
as follows: 407 (355-431); 150 (133-170); 46.0 (42-49).

Female: Ten adults from the Sierra Nevada of California yield
average and extreme measurements as follows: Total length, 349
(336-362); length of tail, 127 (120-133); length of hind foot,
36.3 (32-39). Tail averages 57 per cent as long as head and body.
Length of hind foot less than basal length. Corresponding
measurements of ten adults from the Rocky Mountains of central
Colorado are as follows: 347 (325-375); 123 (111-141); 40
(32-43).

The average differences in external measurements of the two sexes,
in the Sierras of California are: Total length, 51; length of
tail, 23; length of hind foot, 9.8. Weight of 7 adult males from
California is 267 (226-345) grams. Two adult females from there
weigh 148 and 115 grams and 3 from White Pine County, Nevada, 134,
122 and 124, giving an average of 129 grams.

_Externals._--Longest facial vibrissae black, brown or white
(often all three colors in same specimen) and extending beyond
ear; carpal vibrissae same color as underparts and extending to
apical pad of fifth digit; hairiness of foot-soles (in summer
pelage) about as shown in figure 19.

_Color._--Upper parts, in summer, near (14 _n_ to _l_) Brussels
Brown or tones 1 to 3 of Raw Umber of Oberthür and Dauthenay, pl.
301, darker on top of head from nose to line connecting posterior
margins of ears. Chin and upper lips white. Remainder of
underparts Buff-Yellow to Straw Yellow and sometimes
Ochraceous-Buff especially in young, and in some adults from
southern Colorado. In winter, all white, except tip of tail, or
upper parts near (_j_) Snuff Brown or lighter than Brussels Brown
with a smoked effect, and underparts white. Tip of tail at all
times black. Color of underparts extends distally on posterior
sides of forelegs over toes onto antipalmar faces of feet and
wrists, on medial sides of hind legs to ankles, over antiplantar
faces of toes, medial third of tarsus and usually over proximal
tenth to three-fourths of ventral side of tail. Least width of
color of underparts averaging, in a series of twenty males from
the southern half of the Sierra Nevada of California, 59 (37-76)
per cent of greatest width of color of upper parts. In seven males
from southern Colorado corresponding percentages are 55 (37-71).
Black tip of tail in series from Sierra Nevada averaging 50
(40-60) mm. long; thus longer than hind foot and averaging 33-1/3
per cent of length of tail-vertebrae.

_Skull and teeth._--Male (based on 25 adults, from Sierra Nevada
of California): See measurements and plates 19-21; weight, 3.7
(2.9-4.9) grams; basilar length, 43.6 (40.6-46.1); zygomatic
breadth more than distance between condylar foramen and M1 (save
in four instances) and more than distance between anterior
palatine foramen and anterior margin of tympanic bulla (save in
two specimens); mastoid breadth more (80 per cent of specimens) or
less (20 per cent) than postpalatal length; postorbital breadth
less than length of upper premolars and more or less than width of
basioccipital measured from medial margin of one foramen lacerum
posterior to its opposite; interorbital breadth more or less 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 medial length of P4 (except in two
specimens); anterior margin of tympanic bulla as far posterior to
foramen ovale as width of 3 to 5 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;
anterior margin of masseteric fossa not carried farther forward
than point directly below hypoconid of m1.

Female (based on ten adults from Sierra Nevada of California): See
measurements and plates 33-35; weight, 2.2 (1.8-2.4) grams;
basilar length, 38.2 (36.7-39.5); zygomatic breadth more (except
in one specimen) than distance between condylar foramen and M1 and
more (save in two specimens) than distance between anterior
palatine foramen and anterior margin of tympanic bulla;
postorbital breadth less than length of upper premolars and less
than (except in one specimen) width of basioccipital measured from
medial margin of one foramen lacerum posterior to its opposite;
least width of palate more or less than either outside or inside
length of P4 but generally less than inside length; tympanic bulla
as far posterior to foramen ovale as width of 3 to 5-1/2 upper
incisors; height of tympanic bulla more or less (usually 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 more or less than length of rostrum.

The skull of the female averages 41 per cent lighter than that of
the average male.

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.

=Oregon= (by counties from west to east). _Jackson County_:
Rustler Peak, Crater Nat. Forest, 1[46]; Siskiyou (probably south
of), 2. _Klamath County_: 20 mi. W Crescent, 1[101]; Anna Creek,
Mt. Mazama, 2; S Boundary Crater Lake Nat. Park, 1[74]; Fort
Klamath, 15; Upper Klamath Lake, 2[4]; Klamath Falls, 1[75]. _Lake
County_: Dog Lake Ranger Station, 30 mi. SW Lakeview, 1. _Harney
County_: Camp Harney, 2[75]; Burns, 2 (1[101]); 20 mi. S Burns,
1[46]; Narrows, 1[59]; Voltage, 1; Shirk P. O., 2; Keiger Gorge,
Steen Mts., 4. _Malheur County_: Riverside, 1; 2 mi. NW Riverside,
2; Barren Valley, Cord, 1; Cedar Mts., 2; Cow Creek Lake, 1;
Jordan Valley, 1. _County_ in question: Sageview, 1.

=Utah.= _Cache County_: Logan, 1[74]. _Rich County_: 8000 ft.,
near Laketown, 1. _Boxelder County_: Willard, 1[103]. _Salt Lake
County_: Salt Lake City, 1[74]; Barclay, 6500 ft., Wasatch Mts.,
1; Mill Creek, 1[103]. _Utah County_: Provo Bench, 2[6]; Aspen
Grove, Mt. Timpanogos, 1[6]; Payson, 1[6]. _Juab County_: between
Santaquin and Starr, 1[103]. _Uinta County_: Dry Fork Canyon, 20
mi. NW Vernal, 1[9]. _Carbon County_: Sunnyside, 1[44]; Range
Creek, 1[44]. _Millard County_: Deseret, 1[74]. _Sevier? County_:
Fish Lake Plateau, 1. _Grand County_: Warner Ranger Station, La
Sal Mts., 1[6]. _Beaver County_: Britts Meadows, 11000 ft., Beaver
Range, 1[2]; Britts Meadows, Beaver Range, 1; Puffer Lake, 1[44].
_Garfield County_: Boulder, 2[6]. _Washington County_: Pine
Valley, 1[44]; St. George, 1. _San Juan County_: Geyser Pass, La
Sal Mts., 2[6]. _County_ in question: Salt Lake, 2; Wasatch Mts.,
1; La Sal Mts., 11000 ft., 1.

=Washington.= _Okanogan County_: Bald Mt., 6800 ft., 1; Bauerman
Ridge, 6800 ft., Tungsten Mine, 1; Hart Pass, Methow River Trail,
1[46]; Conconully, 2 (1[51], 1[49]); 5 mi. NW Loomis, 1; Molson,
3800 ft., 1; Tunk Mt., 3500 ft., 1. _Whatcom County_: Barron, 5000
ft., 1. _Stevens County_: Colville, 1; Orin, 11[51]. _Pend Oreille
County_: Ione, 6[51]. _Chelan County_: Chelan Mts., 1[2]; Lake
Chelan, 1[46]; Manson, 1; Entiat River, 1680 ft., 20 mi. from
mouth, 7; Dryden, 2[49]; Wenatchee, 1. _Kittitas County_: Easton,
2 (1[51]); Ellensburg, 1[51]; 4 mi. E Ellensburg, 1[51]. _Grant
County_: Neppel, 1[51]. _Lincoln County_: Sprague, 1. _Spokane
County_: Spokane, 1[94]; Cheney 2[89]. _Whitman County_: Pullman,
11 (6[55], 1[68], 1[10]); 6 mi. S Pullman, 1. _Garfield County_:
Snake River, 1. _Yakima County_: Yakima, 1[74]; 1 mi. W Moxee,
1[74].

=Wyoming.= NW Wyoming, 1[75]. _Yellowstone National Park_: Lamar
River, 1; Yellowstone Lake, 1. _Park County_: Greybull River,
1[80]. _Teton County_: Crystal Creek, 2; Jackson, 1; Whetstone
Creek, 2[76]. _Johnson County_: Buffalo, 4 (2[93]). _Fremont
County_: Continental Divide, 20 mi. NW Dubois, 1[75]. _Sublette
County_: Bronx, 1[75]. _Carbon County_: Medicine Bow Mts., 1[75];
15 mi. SE Parco, 1[74]. _Albany County_: Garrett, 1; 12 mi. W
Laramie, 1[74]; 7 mi. W Laramie, 2[74]; 5 mi. W Laramie, 4[74];
"near" Laramie, 1[74]; 3 mi. SW Laramie, 1[74]; 12 mi. S Laramie,
1[74]. _Uinta County_: Fort Bridger, 6800 ft., 1[74]; Lonetree, 1;
Bridger Pass, 1. _County_ in question: Laramie River, 2. No
locality more definite than state, 1.

=Mustela frenata effera= Hall

Long-tailed Weasel

Plates 19, 20 and 21

_Mustela frenata effera_ Hall, Carnegie Instit. Washington Publ.
473:93, November 20, 1936.

_Mustela arizonensis_, Dice, Journ. Mamm., 1:12, November 28, 1919.

_Type._--Male, adult, skull and skin; no. 33637, Amer. Mus. Nat.
Hist.; Ironside, 4000 ft., Malheur County, Oregon; September 8,
1912; obtained by H. E. Anthony; original no. 267.

The skull (plates 19-21) is complete and unbroken. The teeth all
are present and entire. The skin, in summer pelage, is well made.

_Range._--Upper Sonoran to Arctic Alpine life-zones of northern
two-thirds of Oregon east of the Cascades, and southeastern
Washington, south of the Snake River. See figure 29 on page 221.

_Characters for ready recognition._--Differs from _M. f.
nevadensis_ in small size, males averaging 12-1/2 per cent smaller
in external measurements, 8 per cent smaller in linear
measurements of skull, and 22 per cent in weight of skull, total
length averaging 360 rather than 400, condylobasal length
averaging 40.5 rather than 43.6; from _M. f. oregonensis_ in
absence of frontonasal white patch, presence of light color of
underparts on ventral face of tail and smaller skull with basilar
length averaging less than 41.7 in males; from _M. f. washingtoni_
in presence of light color of underparts on ventral face of tail,
in male skull by linear measurements averaging 7 (5-12) per cent
shorter and relative to basilar length shorter in preorbital
region and broader across mastoid processes and zygomatic arches.

_Description._--_Size._--Male: Eight (6 adult and 2 subadult)
males from northeastern Oregon yield average and extreme
measurements as follows: Total length, 360 (340-378); length of
tail, 129 (122-136); length of hind foot, 42 (40-44). Tail
averages 56 (52-59) per cent as long as head and body. Length of
hind foot more or less than (about same as) basal length.

Female: No. 212423 from Vale, and no. 566 V. B. Scheffer, from 15
mi. E Ukiah, measure, respectively: Total length, 312, 306; length
of tail, 113, 114; length of hind foot, 35, 35. Tail averages 57
per cent as long as head and body.

Differences in external measurements between the one adult female
and the average of the males are: Total length, 51; length of
tail, 16; length of hind foot, 7.

_Externals._--Longest facial vibrissae black, brown or white
(often all three colors in same specimen) and extending beyond
ear; carpal vibrissae same color as underparts and extending to
apical pad of fifth digit; hairiness of foot-soles (in summer
pelage) about as shown in stage 4 of figure 19.

_Color._--Upper parts, in summer, near (14 _n_ to _l_) Brussels
Brown or tones 1 to 3 of Raw Umber of Oberthür and Dauthenay, pl.
301, darker on top of head from nose to, or slightly behind, line
connecting posterior margins of ears. Chin and usually all of
upper lips white. Remainder of underparts Buff-Yellow to Straw
Yellow. In winter all white except tip of tail or upper parts near
(_j_) Snuff Brown or lighter than Brussels Brown with a smoked
effect, with underparts white. Tip of tail at all times black.
Color of underparts extends distally on posterior sides of
forelegs over toes onto antipalmar faces of toes and wrists, on
medial sides of hind legs to ankles over antiplantar faces of
toes, distomedial third of tarsus and usually over proximal fourth
to three-fourths of ventral side of tail. Least width of color of
underparts averaging, in 15 males, 53 (36-69) per cent of greatest
width of color of upper parts. Black tip of tail averaging 47
(38-67) mm. long. Thus averaging longer than hind foot, and 36 per
cent of length of tail-vertebrae.

_Skull and teeth._--Male (based on 6 adults from northeastern
Oregon): See measurements and plates 19-21. As described in
_Mustela frenata nevadensis_ except that: Weight, 2.9 (2.5-3.4)
grams; basilar length, 40.5 (39.3-41.8).

Female (based on no. 212423, adult from Vale): In so far as parts
of the broken skull permit a person to judge, the skull is as
described in _M. f. nevadensis_ except that: Smaller; lighter;
postorbital breadth more than width of basioccipital measured from
medial margin of one foramen lacerum posterior to its opposite.

As compared with the skull of _M. f. nevadensis_ that of _effera_ seems, on the average, to have the preorbital part relatively smaller. Otherwise, the skull is a miniature of the skull of _nevadensis_, averaging about eight per cent smaller in linear measurements and weighs twenty-two per cent less. Comparisons of the skull with those of _M. f. washingtoni_ and _M. f. oregonensis_ are made in accounts of those subspecies.