Chapter XVI: Introduction (15)

_Remarks._--This geographic race has long borne the name of _Mustela arizonensis_ (Mearns). Small size differentiates _effera_ from _nevadensis_ and specimens have been allocated to one or the other subspecies on the basis of size, or average size when several individuals are available from one locality. Complete intergradation with each adjoining subspecies is indicated by numerous specimens, more of which are assigned to these adjoining subspecies than to _effera_ itself.

The minimum of size in _M. f. effera_ is found in the Blue Mountain region of northeastern Oregon. Specimens from the area intervening between these mountains and the Cascades average larger but are nearer the mean of typical _effera_ than they are to the means of _washingtoni_, _oregonensis_ or _nevadensis_.

Two males, nos. 204883, adult, and 204884, young, from Sisters, Oregon, near the eastern base of the Cascades, show approach structurally to _M. f. washingtoni_ as it is represented at the nearby locality, Permilia Lake, at the west base of Mount Jefferson. Everything considered, however, the two specimens from Sisters are nearer to _effera_. A male from Condon, Oregon, shows approach to the Cascade race in slightly increased size.

No perfect skulls of adult females are available from the part of northwestern Oregon in which _effera_ reaches its typical state of development as judged by the small size of the skull of the adult male. Skulls of adult females are available, however, from more nearly marginal localities. These, though smaller than in _nevadensis_, show relatively less difference in size when compared with _nevadensis_ than do skulls of males. Even so the females at these marginal localities are smaller than those of _nevadensis_ of comparable age and adequate material of adult female _effera_ from the region where the males attain their extreme of small size probably will show about the same relative difference in size between _nevadensis_ and _effera_ as is known to exist between the adult males of these two subspecies. The small size of a subadult female, no 74631, U. S. Nat. Mus., from Asotin, Washington, constitutes partial basis for this opinion.

Of 14 adults examined none showed malformation of the frontal sinuses due to infestation by parasites.

_Specimens examined._--Total number, 53, arranged within each
state by counties from north to south. Unless otherwise indicated
specimens are in the collection of the United States National
Museum.

=Oregon.= _Wasco County_: 4 mi. S The Dalles, 1[74]; Wapinita, 1;
Antelope, 2; 7 mi. E Antelope, 5. _Gilliam County_: Condon, 1[46].
_Morrow County_: 10 mi. S Hardman, 1. _Umatilla County_: Umatilla,
2; 15 mi. E Ukiah, 4000 ft., 1[49]. _Union County_: Elgin, 1; 20
mi. E Lehman, 1[46]. _Wallowa County_: Horse Creek, 15 mi. N
Paradise, 1; Enterprise, 1[46]; Wallowa Lake, 1[46]; Wallowa
Mts., 8300 ft., 1. _Baker County_: Haines, 1[49]; Anthony, 3[2];
Bourne, 2. _Grant County_: Long Creek, 1[46]; Canyon Creek, 1[46];
Strawberry Mts., 2; Silvies, 1[14]. _Crook County_: Prineville, 4.
_Deschutes County_: Sisters, 2; Bend, 1. _Lake County_: 3 mi. W
Stauffer, 1; Fort Rock, 1[46]. _Harney County_: 25 mi. NW Burns,
1. _Malheur County_: 4000 ft., Ironside, 2[2]; 1-1/2 mi. S Vale,
2.

=Washington.= _Walla Walla County_: Prescott, 4 (2[76], 1[60],
1[74]); Ft. Walla Walla, 2 (1[75]); Wallula, 1[76]. _Asotin
County_: Asotin, 1.

=Mustela frenata washingtoni= (Merriam)

Long-tailed Weasel

Plates 19, 20, 21, 34, 35 and 36

_Putorius washingtoni_ Merriam, N. Amer. Fauna, 11:18, pl. 4, figs.
3, 3a, 4, 4a, June 30, 1896.

_Mustela washingtoni_, Miller, U. S. Nat. Mus. Bull., 79:98,
December 31, 1912.

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

_Type._--Male, adult, skin and skull; no. 76322, U. S. Nat. Mus.,
Biol. Surv. Coll.; Trout Lake, Mt. Adams, Klickitat (?) County,
Washington; December 15, 1895; obtained by D. N. Kaegi; original
no. 2.

The skull is unbroken. The left incisors above are missing.
Otherwise the teeth are present and entire. The skin is well made,
in brown winter pelage, lacks collector's measurements, has no
bones in the feet, but by large size is judged to be a male.

_Range._--Altitudinally from near 2000 feet at Trout Lake up to
the highest parts of the Cascade Range from Mount Jefferson,
Oregon, north to Mount Rainier, Washington; Upper Sonoran
Life-zone to Arctic Alpine Life-zone. See figure 29 on page 221.

_Characters for ready recognition._--Differs from _M. f.
altifrontalis_ in lighter color of upper parts and underparts,
latter ranging from Buff-Yellow to Naples Yellow rather than near
(14 _a_ to 16 _c_) Ochraceous-Buff, in shallower skull in both
sexes (see measurements), in males, a longer preorbital region,
narrower skull with shorter bullae, and in females, a smaller
skull with interorbital breadth averaging less than 24 per cent of
basilar length; from _M. f. nevadensis_ in absence of light color
of underparts on ventral face of tail, in skulls of males, by
longer preorbital region and narrower skull across mastoid
processes and zygomatic arches, in skulls of females, by shorter
preorbital region, and smaller bullae (see measurements); from _M.
f. effera_ in absence of light color of underparts on ventral face
of tail, in skulls of males, by linear measurements averaging 7
(5-12) per cent larger, and relative to basilar length, longer in
the preorbital region and narrower across mastoid processes and
zygomatic arches; from _M. f. oregonensis_ in absence of
frontonasal white patch, longer skull in males, which in
percentage of basilar length has, on the average, orbitonasal
length amounting to more than 35, mastoid breadth less than 55,
and zygomatic breadth less than 63, and in females, smaller skull
with least width of palate less than length of P4, upper
tooth-rows less than 38-1/2 per cent of basilar length, bullae
smaller, averaging less than 13.4 in length.

_Description._--_Size._--Male: Fifteen subadult topotypes yield
average and extreme measurements as follows: Total length, 400
(357-437); length of tail, 149 (122-171); length of hind foot,
47.6 (42-59). Tail averages 59 per cent as long as head and body.
Length of hind foot averaging more than basal length.
Corresponding measurements of one adult and 3 young from Mount
Rainier are: 415 (405-423); 155 (145-164); 51 (50-53).

Female: Five adult topotypes yield average and extreme
measurements as follows: Total length, 349 (330-393); length of
tail, 124 (114-133); length of hind foot, 38 (36-39). Tail
averages 55 per cent as long as head and body. Length of hind foot
averaging about same as basal length. Corresponding measurements
of two adults and 6 young from Mount Rainier are: 338 (320-360);
121 (115-132); 36 (34-40).

The average differences in external measurements of the two sexes,
from Mount Adams, are: Total length, 51; length of tail, 25;
length of hind foot, 9.6. Corresponding differences between the
specimens from Mount Rainier are: 77; 34; 15.

_Externals._--Longest facial vibrissae black or brown (often both
colors in same specimen) and extending beyond ear; carpal
vibrissae same color as underparts and extending to or beyond
apical pad of fifth digit; hairiness of foot-soles slightly less
than shown in figure 19.

_Color._--Upper parts in summer near (14 _n_) Argus Brown or tone
4 of Burnt Umber of Oberthür and Dauthenay, pl. 304; one topotype
Buckthorn Brown or tone 3 to 4 of Snuff Brown of Oberthür and
Dauthenay, pl. 303. Dark spot at each angle of mouth present or
absent, and when present, often fused with color of upper parts,
which rarely covers lower lips. Chin, and usually lower lips,
white. Remainder of underparts Buff-Yellow to Naples Yellow. In
winter, all white except tip of tail which is at all times black,
or upper parts near (14) Brussels Brown to near (_j_) Snuff Brown
with smoked effect and underparts white, rarely with trace of
yellowish. Color of underparts extends distally on posterior sides
of forelegs over toes onto antipalmar faces of feet and usually
all of wrists, on medial sides of hind legs anywhere from knee to
tips of toes. Least width of color of underparts averaging in ten
topotypes, 24 (10-37) per cent of greatest width of color of upper
parts. Black tip of tail in same series averaging 55 (45-60) mm.
long, thus longer than hind foot and averaging 37 per cent of
length of tail-vertebrae.

The color of the underparts is not so narrow in the specimens from
Mount Rainier and it is believed that the slender bodies used in
stuffing the topotypes has accentuated in them the appearance of
narrowness of the light-colored underparts.

_Skull and teeth._--Male (based on 22 adult topotypes): See
measurements and plates 19-21; weight, 3.5 (2.8-4.7) grams;
basilar length, 43.7 (40.0-47.7); zygomatic breadth more or less
than distance between condylar foramen and M1 or than between
anterior palatine foramen and anterior margin of tympanic bulla;
mastoid breadth more or less than postpalatal length; postorbital
breadth less than length of upper premolars and greater 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 bullae; breadth of rostrum less (except in no. 82180)
than length of tympanic bulla; least width of palate more (except
in no. 81954) than length of P4; anterior margin of tympanic bulla
as far posterior to foramen ovale as width of 2 to 5 upper
incisors; height of tympanic bulla more or less than distance from
its anterior margin to foramen ovale; length of tympanic bulla
more (except in two instances) than length of lower molar and
premolar tooth-row and shorter (except in two instances) than
rostrum; anterior margin of masseteric fossa below m2.

Female (based on 11 ad. topotypes): See measurements and plates
34-36; weight, 2.0 (1.8-2.2) grams; basilar length, 37.6
(37.0-38.9); zygomatic breadth less (except in no. 70945) than
distance between condylar foramen and M1 or than between anterior
palatine foramen and anterior margin of tympanic bulla;
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; least width of palate
less (except in one specimen) than greatest length of P4; tympanic
bulla as far posterior to foramen ovale as width of 3-1/2 to 5-1/2
upper incisors; height of tympanic bulla more or less 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.

Compared with _M. f. nevadensis_, the skull of the male of _washingtoni_ averages more slender, as shown by the mastoid and zygomatic breadths and has the preorbital part longer, on the average, as shown by the greater ratio (to the basilar length) of the length of the tooth-rows and orbitonasal length. Also, on the average, the postorbital constriction is longer than in _nevadensis_ and the tympanic bullae are smaller. In females, the skull is lighter, the tooth-rows are shorter, the tympanic bullae are smaller, and the preorbital part of the skull is shorter and narrower as shown by the orbitonasal length and interorbital breadth. Except that the tympanic bullae are actually, although not relatively, smaller in males of _effera_, it differs from _washingtoni_ in the same way as does _nevadensis_ as regards relative proportions, but, of course, the actual difference in size is greater since _effera_ is smaller than _nevadensis_. Comparison of the skull with that of _oregonensis_ is made in the account of that subspecies.

_Remarks._--_M. f. washingtoni_ was described and named in 1896 by Merriam as a distinct species. Subsequently, specimens which here are regarded as intergrades between _altifrontalis_ and _nevadensis_, were classified as _washingtoni_.

The external measurements given for the specimens from Mount Adams are those recorded on the labels in inches and fractions thereof. Instead of total length there sometimes is written "tip to tip." In the series of 19 winter-taken topotypes the hairs project beyond the end of the caudal vertebrae for an average distance of 28 (19-40) millimeters. If the hairs on the end of the tail were included in the measurements, 28 millimeters should be subtracted from the averages. Probably the measurements should stand as given, since an adult male topotype, no. 226758, U. S. Nat. Mus., taken subsequently by Walter P. Taylor measures 405; 152; 51.

_Mustela frenata washingtoni_ is not a strongly marked geographic race. In many features it is intermediate between _M. f. altifrontalis_ and _M. f. nevadensis_. This is especially true of coloration. In the series from Mount Adams and that from Mount Rainier, some individuals have the light color of the underparts extended down the hind legs over the feet and over the proximal face of the ventral third of the tail as in _nevadensis_, whereas others from the same place have the light color of the underparts absent from the tail and extending no farther down the hind limbs than the knees. The light color of the underparts in the series of topotypes is so restricted that the transverse extent at the narrowest place amounts to only 24 (10-37) per cent of the greatest width of the color of the upper parts. This narrowness of the color of the underparts has been likened by Merriam (1896:18) to the condition in _Mustela frenata noveboracensis_. So it is, but it is similar to the condition found also in the geographically adjoining _M. f. altifrontalis_.

Of the 37 skulls of subadults and a few adults, 11 had the frontal sinuses malformed as a result of infestation by parasites.

_Specimens examined._--Total number, 56, arranged within each
state by localities from north to south. Unless otherwise
indicated specimens are in the collection of the United States
National Museum.

=Oregon.= Mt. Jefferson, Permilia Lake, 1.

=Washington.= _Pierce County_: 5500 ft., Spray Park, Mt. Rainier,
1; Spray Park, 1[74]; 5935 ft., Glacier Basin, Mt. Rainier, 5
(1[10]); 5051 to 5100 ft., Owyhigh Lakes, Mt. Rainier, 7 (1[10]),
Tahoma Creek, 1[72]; Nisqually entrance, 1[72]; Longmire, 1[72];
Mt. Rainier Nat'l Park, 2[72]. _Klickitat County_: Trout Lake, S
Base Mt. Adams, 35; 3500 ft., Gotchen Creek, Mt. Adams, 1.

=Mustela frenata saturata= (Merriam)

Long-tailed Weasel

Plates 19, 20, 21 and 30

_Putorius saturatus_ Merriam, N. Amer. Fauna, 11:21, June 30, 1896.

_Mustela saturata_, Miller, U. S. Nat. Mus. Bull., 79:98, December
31, 1912.

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

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

_Type._--Male, adult, skull and skin; no. 65930, U. S. Nat. Mus.,
Biol. Surv. Coll.; Siskiyou, Jackson County, Oregon; June 6, 1894;
obtained by C. P. Streator; original no. 3905.

The skull (plates 19-21, 30) lacks the middle part of each
zygomatic arch. The teeth all are present although much worn,
probably from gnawing at the trap which captured the animal. The
skin, in fresh summer pelage, is fairly well made.

_Range._--Transition and Boreal life-zones of Siskiyou and Trinity
mountains in southern Oregon and northwestern California. See
figures 29 and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f.
nevadensis_ in lacking light color of underparts on tail and ankle
and in greater average breadth across mastoid processes of skull
(see measurements); from _M. f. oregonensis_ in lacking white
nasofrontal spot, in having color of underparts interrupted at
ankle; from _M. f. munda_ in lacking white nasofrontal spot, in
smaller and relatively deeper skull of males and smaller skull of
the female.

_Description._--_Size._--Male: Four adult males (the type, 1 from
Mt. Ashland and 2 from Jackson Lake) yield average and extreme
measurements as follows: Total length, 414 (402-437); length of
tail, 150 (136-160); length of hind foot, 46 (43-50). Tail
averages 57 (49-62) per cent as long as head and body. Length of
hind foot more or less than basal length.

Female: One young from the summit of the Trinity Mountains east of
Hoopa and one nontypical adult from 5500 feet elevation on South
Fork Mountain, Humboldt County, measure respectively as follows:
Total length, 330, 325; length of tail, 115, 123; length of hind
foot, 37, 37. Tail is 53 and 61 per cent as long as head and body.
Length of hind foot less than basal length.

Average differences in external measurements between the two
sexes, indicated by the unsatisfactory material available, are:
Total length, 86; length of tail, 31; length of hind foot, 9.

_Externals._--Longest facial vibrissae black or dark brown and
extending beyond ear; carpal vibrissae same color as underparts
and extending as far as apical pad of fifth digit; hairiness of
foot-soles, in summer pelage, as shown in figure 19.

_Color._--Upper parts, in summer, Brussels Brown to near (_n_)
Brussels Brown or lighter than tone 3 of Raw Umber of Oberthür and
Dauthenay, pl. 301, usually darkest on nose and forehead. Chin
white. Remainder of underparts Buff-Yellow to Warm Buff. Tip of
tail black. Winter pelage unknown. Color of underparts extends
distally on posterior sides of forelegs over toes onto antipalmar
faces of feet and sometimes wrists, on medial sides of hind legs
only to ankles, but toes sometimes with isolated white markings.
Least width of color of underparts in the type and 2 adults from
Jackson Lake averaging 35 (30-40) per cent of greatest width of
color of upper parts. Black tip of tail averaging 54 (53-55) mm.
long; thus longer than hind foot and averaging 37 per cent of
length of tail-vertebrae.

_Skull and teeth._--Male (based on 4 adults: Type, Mt. Ashland, 1;
Jackson Lake, 2): See measurements and plates 19-21, 30. As
described in _Mustela frenata nevadensis_ except that: Weight, 3.8
(3.5-4.3) grams; basilar length, 44.4 (42.6-45.8); zygomatic
breadth more or less than distance between condylar foramen and M1
or than distance between anterior palatine foramen and anterior
margin of tympanic bulla; mastoid breadth more than postpalatal
length; least width of palate less than medial length of P4
(except in one specimen).

Female (based on one adult possibly not typical, from 5500 ft.,
South Fork Mt.): See measurements. As described in _Mustela
frenata nevadensis_ except that: Weight, 2.2 grams; basilar
length, 38.1; zygomatic breadth less than distance between
condylar foramen and M1 and less than distance between anterior
palatine foramen and anterior margin of tympanic bulla;
postorbital breadth more than width of basioccipital measured from
medial margin of one foramen lacerum posterior to its opposite.

The skull of the male of _saturata_, relative to the basilar length, is broader across the mastoids and narrower across the rostrum and interorbital region than that of _nevadensis_. Skull not known certainly to differ from that of _oregonensis_. Compared with the skull of _munda_, that of the male of _saturata_ is smaller in every part measured except depth of tympanic bullae which averages 3.6 millimeters, rather than 3.5 as in _munda_. Also, the skull of _saturata_ has a less-marked postorbital constriction, is less heavily ridged, less angular, does not have the impressions of the temporal muscles carried so far forward on the frontal bones and is relatively much narrower across the zygomatic arches.

_Remarks._--In 1896, Merriam named _M. f. saturata_ as a distinct species on the basis of one specimen, taken by Clark P. Streator at Siskiyou, Oregon, and a second specimen taken the year previously by Allan C. Brooks at Chilliwack, British Columbia. On the basis of these two specimens, Merriam (1896:22) ascribed to the race a range ". . . on the Cascade and Siskiyou mountains of Oregon and Washington, reaching a short distance into British Columbia." Since that time, this name, _saturata_, has been employed for the dark-colored weasels, of the coastal region of Oregon, Washington, and extreme southwestern British Columbia, which here are arranged under the name _M. f. altifrontalis_. _M. f. saturata_ proves to be restricted to the humid mountainous region inland from the coast in northern California and in the Siskiyou Mountains of southern Oregon. Its range is separated by that of _M. f. oregonensis_ from the range of the darker-colored, deeper-skulled, _M. f. altifrontalis_ of the humid costal region proper.

On May 5, 1933, Mr. Clark P. Streator, informed the writer that he remembered taking the type specimen of _Mustela frenata saturata_ (Merriam) in the town of Siskiyou, Oregon. The exact place, he said, was reached, at the time of his work there, by going one or two blocks east of the depot, then through a garden into the thick woods where there were springs and numerous burrows of the rodent, _Aplodontia_. Two other weasels labeled as taken at Siskiyou, on September 28 and 29, 1893, by Mr. Streator, are much lighter colored than the type of _saturata_ and have the color of the underparts extended distally on the hind legs to the tips of the toes and in other features of coloration are more like _nevadensis_, the subspecies to which they are referred, than _saturata_. Probably these did not come from exactly the same place that the type specimen of _saturata_ did. Although Mr. Streator does not remember the taking of these particular specimens in 1893, he does remember that on this visit to Siskiyou, he walked southward through the railroad tunnel and collected on the opposite side of the ridge from Siskiyou. Here on more southern exposures, the country was markedly different than in the thick forest at Siskiyou. Probably these two specimens taken in 1893, and referred to _nevadensis_, came from a little way south of Siskiyou and from a different habitat and life-zone than the type specimen of _M. f. saturata_.

Of the 6 specimens examined, only one, the type, shows malformation of the frontal sinuses such as result from infestation by parasites.

_Specimens examined._--Total number, 6, as follows:

=California.= _Siskiyou County_: Jackson Lake, 5900 ft., 2, Mus.
Vert. Zoöl. _Humboldt County_: South Fork Mt., 5500 ft., 1, Mus.
Vert. Zoöl. _County_ in question, Trinity Mts., summit east of
Hoopa, 5800 ft., 1, U. S. Nat. Mus.

=Oregon.= _Jackson County_: Mt. Ashland, 1, Univ. Oreg.; Siskiyou,
1, U. S. Nat. Mus.

=Mustela frenata altifrontalis= Hall

Long-tailed Weasel

Plates 1, 19, 20, 21, 34, 35 and 36

_Mustela frenata altifrontalis_ Hall, Carnegie Instit. Washington
Publ. 473:94, November 20, 1936.

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

_Putorius saturatus_ Merriam, N. Amer. Fauna, 11:21, June 30, 1896
(part).

_Mustela saturata_, Miller, U. S. Nat. Mus. Bull., 79:98, December
31, 1912.

_Type._--Male, adult, skull and skin; no. 42093, Mus. Vert. Zoöl.;
Tillamook, Tillamook County, Oregon; July 10, 1928; obtained by
Alex Walker; original no. 717.

The skull is complete and unbroken. P3 on the left side is
missing; otherwise the teeth all are present and entire. The skin
is well made and the enlarged scrotal pouch shows the collector's
sexing of the specimen to have been correct.

_Range._--Altitudinally from sea level up to at least 4800 feet
(Mount Baker) in the Transition Life-zone of the humid, coastal
region of Oregon, Washington and extreme southwestern British
Columbia. See figure 29 on page 221.

_Characters for ready recognition._--Differs from _M. f.
nevadensis_ in tone 4 of Brownish Drab, pl. 302, rather than tones
1-3, of Raw Umber, pl. 301, of Oberthür and Dauthenay of upper
parts, in near (14 _a´_ to 16 _c´_) Ochraceous-Buff rather than
Buff-Yellow to Straw Yellow of underparts, in that least width of
color of underparts amounts to less than 37 per cent of greatest
width of color of upper parts, in absence of color of underparts
on ventral side of tail and on hind leg distal to knee, and in
greater depth of skull through frontal region; from _M. f.
washingtoni_ in darker color of upper parts and underparts, latter
near (14 _a_´ to 16 _c_´) Ochraceous-Buff rather than ranging from
Buff-Yellow to Naples Yellow, in deeper skull in both sexes (see
measurements), in males a shorter preorbital region, broader skull
with longer bullae and in females a larger skull with interorbital
breadth averaging more than 24 per cent of basilar length; from
_M. f. oregonensis_ in frontonasal white patch absent, color above
darker (tone 4 of Brownish Drab, pl. 302, rather than tone 2 to 3
of Raw Umber, pl. 301 of Oberthür and Dauthenay), light-colored
underparts narrower and not extended distally beyond knee, in
females tooth-row shorter, amounting to less than 38 per cent of
basilar length.

_Description._--_Size._--Male: Eight adult topotypes yield average
and extreme measurements as follows: Total length, 426 (392-445);
length of tail, 160 (148-170); length of hind foot, 47 (42-53).
Tail averages 60 per cent as long as head and body. Length of hind
foot averages more than basal length.

Female: Five adults from Tillamook and Blaine, Oregon, yield
average and extreme measurements as follows: Total length, 347
(320-370); length of tail, 125 (114-131); length of hind foot, 38
(35-44). Tail averages 56 per cent as long as head and body.
Length of hind foot less than basal length.

The average differences in the external measurements are: Total
length, 79; length of tail, 35; length of hind foot, 9.

_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 or
beyond apical pad of fifth digit; hairiness of foot-soles (in
summer pledge) slightly less than shown in figure 19.

_Color._--Upper parts, in summer, near (_n_) Argus Brown or tone 4
of Brownish Drab of Oberthür and Dauthenay, pl. 302. Dark spot at
each angle of mouth well developed; often fused with color of
upper parts which sometimes covers lower lips. Chin white.
Remainder of underparts near (14 _a´_ to 16 _c´_) Ochraceous-Buff.
In winter, upper parts near (14) Argus Brown with smoked effect
and Warm Buff to Naples Yellow below. 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 usually all
of wrists, on medial side of hind legs typically only to knee but
sometimes to ankle. Tips of toes of hind feet almost always marked
with color of underparts. Least width of color of underparts
averaging in a series of 14 males from Blaine, Oregon, 23 (14-36)
per cent of greatest width of color of upper parts. Black tip of
tail in 8 adult males from Blaine, Oregon, averaging 59 (47-70)
mm. long; thus longer than hind foot and averaging 37 per cent of
length of tail-vertebrae.

_Skull and teeth._--Male (based on 9 adults from Blaine, Tillamook
Co., Oregon): See measurements and plates 19-21; weight, 4.4
(3.3-5.3) grams; basilar length, 45.6 (42.4-47.7); zygomatic
breadth more or less (usually more) than distance between condylar
foramen and M1 or than between anterior palatine foramen and
anterior margin of tympanic bulla; mastoid breadth more or less
(usually more) than postpalatal length; postorbital breadth less
(except in some instances of malformations of frontal sinuses
which result from infestation by parasites) 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
more or less than length of P4; anterior margin of tympanic bulla
as far posterior to foramen ovale as width of 3 to 4 (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
more or less than orbitonasal length; anterior margin of
masseteric fossa directly below m2.

Female (based on 4 adults): See measurements and plates 34-36;
weight, 2.2 (2.2-2.3) grams; basilar length, 38.1 (37.8-39.7);
zygomatic breadth more or less (less in three of four specimens)
than distance between condylar foramen and M1 or than between
anterior palatine foramen and anterior margin of tympanic bulla;
relation of postorbital breadth to other measurements in doubt
because of malformation of frontal sinuses by parasites; least
width of palate not less than greatest length of P4; tympanic
bulla as far posterior to foramen ovale as width of 3-1/2 to 5-1/2
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.

Compared with the skull of _M. f. washingtoni_ that of each sex of _altifrontalis_ averages slightly larger in every measurement taken, except measurements of teeth which are approximately the same, and is relatively deeper through the frontal region and through the braincase as measured at the anterior margin of the basioccipital. Skulls of females of _altifrontalis_ have a relatively broader interorbital region. Skulls of males of _altifrontalis_ further differ in having relatively, as well as actually, longer tympanic bullae, relatively lesser orbitonasal length and a greater relative breadth across the mastoids and across zygomata. Compared with _M. f. nevadensis_, the skull of the male of _altifrontalis_ averages slightly larger and heavier although the skulls of females are of approximately the same size and weight. Relative to the basilar length, the skulls of both sexes are deeper through the braincase and narrower across the mastoids; the rostrum is broader, especially in males; the tooth-rows are shorter and the interorbital breadth less, especially in females. Comparison with the skull of _oregonensis_ is made in the account of that subspecies.

_Remarks._--Until the present study was begun, animals of this race have gone under the name _Mustela saturata_ (Merriam). The United States National Museum has a juvenile taken, in 1858, by Wayne at Astoria, O. T.; the Samuel N. Rhoads collection contained one specimen taken in 1891, at Tacoma, Washington; one in the Bangs' collection was taken at Chilliwack, British Columbia, in 1895, and the Field Museum has one taken on the Olympic Peninsula in 1898. The best material is that collected by Alex Walker, at Tillamook, Oregon.

Intergradation with _nevadensis_ is indicated by several specimens. The coloration of the one adult female, no. 90, Chas. R. Conner Mus., from Swamp Creek, Washington, has the color of the underparts extended down the hind legs over the feet, and over the proximal third of the ventral face of the tail as in _nevadensis_ although the other two specimens from the same place have the color pattern of _altifrontalis_. Of the four specimens from British Columbia referred to this subspecies, only the specimen from Chilliwack is typical as regards color pattern. The one from Cultus Lake has the color pattern of _nevadensis_ and might be referred to that race almost as well as to _altifrontalis_. The two specimens from Lihumption Park are intermediate between the two races in tone of color. Neither has the color of the underparts extended onto the tail or continuously over the hind feet as in _nevadensis_ but each does have the color of the underparts less restricted and of lighter hue than in _altifrontalis_. Only one of the specimens, no. 7848 Canad. Nat. Mus., from Lihumption Park is adult and it has a skull which agrees with that of _altifrontalis_ rather than _nevadensis_.

After writing the above, a good representation of the weasel population along the eastern side of Puget Sound was made available by friends in that area. Study of the weasels from there shows that their color is intermediate between that of _altifrontalis_ and _nevadensis_. On the whole, they (specimens from Bellingham, for example) resemble one subspecies about as much as the other. In cranial characters some specimens, in certain features, approach _nevadensis_ but most specimens agree with _altifrontalis_ and all are more nearly like _altifrontalis_ to which race all are referred.

The color of these animals is to me indistinguishable from that of _washingtoni_. The color of _washingtoni_ is merely intermediate between that of _nevadensis_ and _altifrontalis_. Nevertheless, the race _washingtoni_ has cranial characters (long narrow skull) which set it off from both _altifrontalis_ and _nevadensis_. This shape of skull is not found in the specimens from along the eastern side of Puget Sound; these animals have skulls like that of _altifrontalis_ and when departures from this occur they are in the direction of _nevadensis_ and not _washingtoni_.

The above, then, explains why specimens which are colored like those of _washingtoni_ are not referred to that race but instead to the race _altifrontalis_.

Of 23 adult skulls examined, 19 have the frontal sinuses malformed as the result of infestation by parasites.

_Specimens examined._--Total number, 80, arranged within states by
counties from north to south. Unless otherwise indicated specimens
are in the United States National Museum.

=British Columbia.= _Chilliwack_, 1[74], Lihumption Park, 4750
ft., 2[77]; Cultus Lake, 1[77].

=Oregon.= _Clatsop County_: Old Fort Clatsop, 1[74]; Astoria, 1.
_Tillamook County_: Tillamook, 12 (7[14], 2[74], 2[2], 1[46]);
Netarts, 1[46]; Blaine, 16 (13[14], 1[93], 1[76], 1[59]). _Lane
County_: Reed, 1; Mercer, 1[46]. _Curry County_: Langlois, 1[46].

=Washington.= _Whatcom County_: Nooksack River, 2000 ft., 14 mi. E
Glacier, 1; Swamp Creek, 2050 ft., Nooksack River, 3[10]; Lookout,
4800 ft., Mt. Baker, 2[10]; Bellingham, 8[25]; 5 mi. S Bellingham,
1[49]. _Skagit County_: Rockport, 300 ft., 1. _King County_:
Bothell, 2[94]; N Seattle 1[51]; Seattle, 1[49]; Tye, 1[51], 2 mi.
E Skykomish, 1[51]; 7 mi. E Kent, 1[76]; Auburn, 3[94]. _Pierce
County_: Tacoma, 1[1]. _Clallam County_: Sequim, 1[49]; Soleduc
Riv., near [_sic._] Sappho, 1[49]; Happy Lake, 1[60]; mouth of
Boulder Creek, Elwha River, 560 ft., Olympic Mts., 1; Hume's
Ranch, 1000 ft., Elwha River, 1; Bogachiel Riv., 1[49]. _Mason
County_: Lake Cushman, 2; 4 mi. N Shelton, 1[51]. _Thurston
County_: Olympia, 2[49]; Tenino, 1[51]. _Pacific County_: 2-1/2
mi. SE Chinook, 3[74].

=Mustela frenata oregonensis= (Merriam)

Long-tailed Weasel

Plates 19, 20, 21, 30, 34, 35 and 36

_Putorius xanthogenys oregonensis_ Merriam, N. Amer. Fauna, 11:25,
June 30, 1896; Bangs, Proc. New England Zoöl. Club, 1:57, June 9,
1899.

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

_Mustela xanthogenys munda_, Grinnell, Univ. California Publ.
Zoöl., 40:102, September 26, 1933 (part).

_Mustela frenata oregonensis_, Hall, Carnegie Instit. Washington
Publ. 473:107, November 20, 1936.

_Type._--Male, subadult, skull and skin; no. 32019/43828, U. S.
Nat. Mus., Biol. Surv. Coll.; Grants Pass, Rogue River Valley,
Josephine County, Oregon; December 19, 1891; obtained by C. P.
Streator; original no. 1404.

The skull (plates 19-21, 30) is complete and unbroken. P3 on the
left side is missing. Otherwise the teeth all are present although
worn probably as a result of gnawing at the trap which captured
the specimen. The skin, in brown, winter pelage, is fairly well
made.

Although the label on the skin and the label in the skull vial
each give the sex of the specimen as female, and although Merriam
(1896:25) regarded the specimen as a female, the present writer
regards the specimen as a male.

It is as large as other undoubted males and larger than any known
female of this subspecies. The labels with the skull and skin give
the locality as "Rogue River Valley, Oregon." The listing here of
the more restricted locality, Grants Pass, is made on the basis of
Merriam's (1896:25) original description of the subspecies.

_Range._--Transition and Canadian life-zones along coast of
northern California and southern Oregon from Humboldt County,
California, north through Curry County, Oregon, thence inland,
west of the Cascades, north to the Columbia River. See figures 29
and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f.
altifrontalis_ in presence of frontonasal white patch, lighter
color above (tone 2 to 3 of Raw Umber, pl. 301, rather than tone 4
of Brownish Drab, pl. 302, Oberthür and Dauthenay), wider extent
of light color of underparts which is extended distally beyond
knee, and in females, longer tooth-row which amounts to more than
38 per cent of basilar length; from _M. f. munda_ in shorter hind
foot of males which is less than 50, and in both sexes, smaller,
less rugose skull (see measurements and plates); from _M. f.
saturata_ in presence of frontonasal white patch, in having color
of underparts extended uninterruptedly over ankle onto foot; from
_M. f. nevadensis_ in presence of frontonasal white patch, lack of
light color of underparts on ventral face of tail, and longer
skull, which relative to its length in males, is shallower through
braincase; from _M. f. effera_ in presence of frontonasal white
patch, lack of light color of underparts on ventral face of tail,
and larger skull with basilar length averaging more than 41.7 in
males; from _M. f. washingtoni_ in presence of frontonasal white
patch, shorter skull in males, which in percentage of basilar
length has, on the average, orbitonasal length amounting to less
than 35, mastoid breadth more than 55, and zygomatic breadth more
than 63; and in females larger skull with least width of palate
more than length of P4, upper tooth-rows more than 38-1/2 per cent
of basilar length, bullae larger and averaging more than 13.4
long.

_Description._--_Size._--Male: Five males (3 adults and 2
subadults from Eureka, Ferndale, and Carlotta, California) yield
average and extreme measurements as follows: Total length, 392
(347-430); length of tail, 138 (110-160); length of hind foot, 46
(43-50). Tail averages 54 (46-61) per cent as long as head and
body. Length of hind foot more or less than basal length. The type
specimen, and an adult from Goldbeach measure, respectively, as
follows: Total length, 412, 386; length of tail, 155, 137; length
of hind foot, 44, 46.

Female: Three adults (2 from Fortuna and 1 from Carlotta,
California) yield average and extreme measurements as follows:
Total length, 367 (360-374); length of tail, 130 (123-134); length
of hind foot, 40 (39-40). Tail averages 55 (52-57) per cent as
long as head and body. Length of hind foot less than basal length.
A subadult from Goldbeach, an adult from 13 mi. SW Grants Pass,
and an adult from Medford, measure, respectively, as follows:
Total length, 316, 344, 294; length of tail, 114, 120, 122; length
of hind foot, 36, 40, 38.

The average differences in external measurements of the two sexes
in the vicinity of Carlotta, are: Total length, 25; length of
tail, 8; length of hind foot, 6. Corresponding differences, at
Goldbeach, are: 70, 23, 10. Probably the females at Fortuna
reflect the large size of _munda_ more than do the males at
Carlotta and the differences between the measurements of the two
sexes probably, therefore, are actually more than are indicated by
the figures above.

_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, as shown in figure 20.

_Color._--Upper parts, in summer, near (16 _l_) Brussels Brown or
tone 2 of Raw Umber of Oberthür and Dauthenay, pl. 301, to
slightly darker than tone 3 of same plate. Darker on nose and top
of head, usually with frontonasal white patch but lacking white
bar in front of each ear, except in the type and 2 specimens from
Salem. Chin, lower lips, angle of mouth, and usually posterior
seventh of upper lip white. Remainder of underparts Pale
Orange-Yellow. In winter usually lighter above with underparts
Warm Buff to Straw Yellow. 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 side of
hind leg, typically over ankle in extremely narrow line which
widens out over distal phalanges of antiplantar faces of toes but
sometimes interrupted at ankle. Least width of color of underparts
averaging, in twenty available specimens, 39 (27-54) per cent of
greatest width of color of upper parts. Black tip of tail in five
adults averaging 50 (43-60) mm. long; thus averaging longer than
hind foot and 33 per cent of length of tail-vertebrae.

_Skull and teeth._--Male (based on 4 adults and subadults from
Eureka, Requa, Goldbeach, and Grant Pass): See measurements and
plates 19-21, 30. As described in _Mustela frenata nevadensis_
except that: Weight, 3.5 (3.5-4.1) grams; basilar length, 42.9
(41.8-44.0); least width of palate more or less than medial length
of P4.

Female (based on 2 adults, one from Carlotta and one from 13 mi.
SW Grants Pass): See measurements and plates 34-36. As described
in _Mustela frenata nevadensis_ except that: Weight, 2.4 (2.2-2.6)
grams; basilar length, 37.7 and 39.5; zygomatic breadth less than
distance between condylar foramen and M1 and less than distance
between anterior palatine foramen and anterior margin of tympanic
bulla. See under "_Remarks_" for additional data on variation in
size of skulls of females.

The skulls of the female averages 31 per cent lighter than that of
the average male.

Because there is much geographic variation between specimens here referred to _oregonensis_, the person who is guided by the present account should keep in mind that results, here reported, of comparisons of the skull with those of other races, were obtained by employing specimens of _oregonensis_ from Carlotta and Eureka, California. These specimens from California are judged to have more of the characters of the subspecies _munda_ than do specimens of _oregonensis_ from more northern localities.

Compared with that of _M. f. washingtoni_ the skull of the male is shorter, especially in the preorbital region and is relatively broader across the mastoidal processes and zygomatic arches. The skull of the female is longer in the preorbital region, has a less cylindrical braincase and differs less from the male skull than is the case in _M. f. washingtoni_. Compared with _M. f. effera_, the skull of the male is smaller in every part measured and relative to the basilar length is broader across the mastoids and has relatively shorter tympanic bullae. From _M. f. nevadensis_ the skull of the male differs in the same way except that size is about the same. The skull of the female _oregonensis_ is more heavily ridged and is relatively broader across the mastoids than that of _effera_. From _M. f. saturata_, _oregonensis_ is not surely known to differ in cranial characters. From _M. f. munda_, _oregonensis_ differs in having the skull of both sexes smaller, and on the average, in all parts measured, has a less marked postorbital constriction, relatively narrower interorbital region and relatively more expanded zygomata. From _M. f. altifrontalis_, males of _oregonensis_ differ on the average, in having larger teeth, and relative to the basilar length, a greater mastoid breadth and a shallower braincase as measured at the anterior margin of the basioccipital. Females of _oregonensis_ differ in larger average size of skull, except for breadth of rostrum and interorbital breadth which, therefore, are relatively less in _oregonensis_, as also is the relative depth of the skull measured at the posterior borders of the upper molars and at the anterior margin of the basioccipital. However, skulls of females of _oregonensis_ have relatively longer tooth-rows and are relatively broader across the zygomata and mastoidal processes.

_Remarks._--In 1896, Merriam named _oregonensis_ as a subspecies of the California bridled weasel on the basis of a single specimen taken by Clark P. Streator. Three additional specimens were acquired in later years, by workers of Dr. Merriam's bureau, from near the type locality and specimens from farther north in Oregon have been accumulated at the University of Oregon. The most satisfactory material is that saved from Humboldt County by the late H. E. Wilder, which, when brought together, is adequate to give some idea of the range of variation that can be expected in a given population.

Of two specimens from Goldbeach, one shows approach to _altifrontalis_ in that the color of the underparts stops at the ankle, and in one, the angle of the mouth is dark colored. Specimens from Eugene and vicinity lack the white facial markings, and in this feature approach the adjoining _washingtoni-effera-nevadensis_ stock. A specimen from 6 miles south of Medford shows approach to _saturata_ in the interruption, on the ankle and lower tibial region, of the color of the underparts. One adult female, no. 1413, Univ. Oregon, from the Rogue River Valley, 13 miles southwest of Grants Pass, stands out prominently, among the other specimens from extreme southern Oregon and northwestern California, by reason of the near (18) Apricot Yellow color of the underparts, but this same color occurs in specimens from the more northerly localities of Buchanan, Eugene, Vida Fish Hatchery, and McKenzie Bridge, as well as in no. 2178, Univ. Oregon, from Cresent Lake. The last mentioned specimen is here referred to _nevadensis_.

Two females referred to _oregonensis_ from southern Oregon differ so greatly in size of skull that they challenge one's imagination in any attempt to provide an explanation for so wide a range of variation in one subspecies. One of these, no. 244520, U. S. Nat. Mus., is an adult female from Medford. The other, no. 224034, U. S. Nat. Mus., is a subadult female (though labeled male) from 43 miles northeast of Grants Pass. The skull of the adult from Medford has a basilar length of 41.5, upper tooth-rows, 16.1 in length, and a weight of 2.75 grams, whereas corresponding figures for the subadult are only 33.8, 12.9, and 1.4. Two other adult females are intermediate in size: No. 1413, Univ. Oregon, from 13 miles southwest of Grants Pass, Oregon, approaches the specimen from Medford in size, and the second specimen, no. 34325, Mus. Vert. Zoöl., from Carlotta, California, is smaller.

Not only is there a difference in length between the skulls of the two extremes of the females but this difference extends to all other dimensions of their skulls, and is most pronounced in the preorbital region. The differences in breadth of the braincase and other parts of the skull are relatively less than the differences in length. Differences of the same nature, although of lesser degree than found in the females, are to be seen in two males. The skull of an adult no. 51590, Mus. Vert. Zoöl., from 6 miles south of Medford, has a basilar length of 46.4, upper tooth-rows, 17.6 mm. long, and a weight of 4.0 grams, whereas corresponding figures for the subadult type specimen from Grants Pass, are only 43.0, 16.2, and 3.3.

The wide range of variation in size of skull of both sexes, together with the considerable variation in color pattern of the specimens here referred to _oregonensis_ raises the suspicion that we are using the name in a composite sense; nevertheless, to recognize more than one subspecies with the material now available would be unwise.

A subadult female, of abnormal color, no. 47149, Mus. Vert. Zoöl., taken by Mr. H. E. Wilder at Carlotta, California, on December 20, 1930, in a region where weasels do not turn white in winter, is white, except for the black tip of the tail, but has a suffusion of orange. This specimen, discussed at greater length on page 43, is instructive in that it suggests that there are separate determiners for the brown and red elements of the pelage. It is interesting also as suggesting how natural selection may tend to eliminate from the population a conspicuous color-variation of this kind. At any rate, Mr. Wilder (Ms.) states: "This specimen was picked up in a field, where it evidently had been dropped by a hawk or an owl." The braincase of the skull is crushed in three places as though by a raptor's beak. None of the several other weasels, all normally colored, saved by Mr. Wilder from this general locality gives evidence of having fallen a victim to a raptor.

Only 2 skulls of the 12 adults and subadults examined show malformation of the frontal sinuses such as results from the presence of parasites.

_Specimens examined._--Total number, 29, arranged within states
from north to south by counties. Unless otherwise indicated
specimens are in the collection of the United States National
Museum.

=California.= _Del Norte County_: Requa, 1[8]. _Humholdt County_:
Eureka, 2 (1[74], 1[75]); Ferndale, 1[74]; Fortuna, 2[63];
Carlotta, 6 (3[74], 3[59]); 12 mi. E Bridgeville, 1[59]; 2 mi. W
Bridgeville, 1[59].

=Oregon.= _Washington County_: Forest Grove, 1. _Marion County_:
Salem, 2. _Benton County_: Buchanan, 1. _Lane County_: McKenzie
Bridge, 1[101]; Vida Fish Hatchery, 1[101]; Eugene, 1[101].
_Douglas County_: Anchor, 1. _Curry County_: Gold Beach, 2[60].
_Josephine County_: Rogue River Valley (Grants Pass), 1; 13 mi. SW
Grants Pass, 1[101]. _Jackson County_: Medford, 2; 6 mi. S
Medford, 1[74].

=Mustela frenata munda= (Bangs)

Long-tailed Weasel

Plates 1, 19, 20, 21, 22, 23, 30, 34, 35, 36 and 40

_Putorius xanthogenys mundus_ Bangs, Proc. New England Zoöl. Club,
1:56, June 9, 1899; Stephens, California mammals, p. 247, 1906.

_Mustela frenata_, Audubon and Bachman, Journ. Acad. Nat. Sci.
Philadelphia, 8 (Pt. 2):291, 1842 (North California about 40°
latitude).

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

_Mustela frenata munda_, Hall, Carnegie Instit. Washington Publ.
473:107, November 20, 1936.

_Type._--Male, adult, skull, os penis and skin; no. 5459,
collection of E. A. and O. Bangs, but now in collection of Mus.
Comp. Zoöl.; Point Reyes, Marin County, California; June 19,
1896; obtained by C. A. Allen; original no. 931. (See comments
under "Remarks," below, on places in California to which the name
Point Reyes has been applied.)

The skull (pls. 19-21, 30) is complete and unbroken. I1 on each
side and right I2 are broken away; p2 and p3 on each side have
been aborted and the only alveoli remaining are two for the right
p3. Otherwise all teeth are present and entire. The skin is fairly
well made and in good condition.

Cranially, the type is a "runt"; its small size and the
circumstance that the tympanic bulla is longer than the lower
molar and premolar tooth-row and longer than the rostrum are
features which differentiate the type from any other specimen seen
of this race.

_Range._--Sea level to at least 6,000 feet (South Yolla Bolly
Mountain, Trinity County, California); Upper Sonoran and
Transition life-zones of the coast and Coast Range of northwestern
California from the Golden Gate northward into southern Humboldt
and Trinity counties. See figures 29 and 30 on pages 221 and 314.

_Characters for ready recognition._--Differs from _M. f.
oregonensis_ in longer hind foot of males which is more than 50
mm., and in both sexes, larger, more prominently ridged skull (see
measurements and plates); from _M. f. saturata_ by presence of
nasofrontal white spot, larger and relatively shallower skull of
males and larger skull of female; from _M. f. nevadensis_ by
presence of well-developed, white, facial markings; absence of
color of underparts on ventral face of proximal third of tail; and
hind foot of males more than 50; from _M. f. xanthogenys_ by near
(_l_) Sudan Brown to near (_l_) Antique Brown rather than
Buckthorn Brown colors of upper parts and greater size, and in
adult male basilar length more than 45 and hind foot more than 47;
from _M. f. nigriauris_ by having inside of ears same color as
back rather than much darker than back.

_Description._--_Size._--Male: Three adults and two young from
Point Arena and Gualala, Mendocino County, yield average and
extreme measurements as follows: Total length, 447 (434-470);
length of tail, 167 (150-185); length of hind foot, 53 (50-60).
Corresponding measurements of three adults from 5 and 6 miles west
of Inverness, Marin County, are: 430 (420-440), 154 (141-160), 48
(48-49). Corresponding measurements of four individuals (3 adults
and 1 young of large size) from South Yolla Bolly Mountain,
Trinity County, are: 383 (374-400), 134 (130-138); 44 (43-44). The
tail averages 60 per cent as long as the head and body in the
series from Point Arena, 56 per cent in the series from Point
Reyes, and 53 per cent in the series from South Yolla Bolly
Mountain. In every specimen except two, length of hind foot less
than basal length. The two exceptions are no. 19720, M.V.Z., male
adult from Point Arena in which the hind foot is recorded as 60
(probably an error in measurement), and no. 19721, M.V.Z., from
the same place, in which the skull has not yet attained its full
growth.

Female: One adult from Point Arena measures as follows: Total
length, 383; length of tail, 134; length of hind foot, 43.
Corresponding measurements of an adult from seven miles north of
Laytonville, Mendocino County, are: 336, 121, 33 (= 36 on dried
skin). Corresponding measurements of an adult from South Yolla
Bolly Mountain, Trinity County, are, 326, 113, 37. In these three
specimens, the tail is, in the order given, 54, 56, and 53 per
cent as long as the head and body. Length of hind foot more than
basal length.

Differences in external measurements of the two sexes as indicated
by the five males and one female from Point Arena, are: Total
length, 64; length of tail, 33; length of hind foot, 10. Weights
of 2 adult males are 265 and 221 grams and of one adult female 155
grams.

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

_Color._--Spot between eyes, narrow band or spot confluent with
color of underparts on each side of head anterior to each ear,
chin, lower lips, and rarely posterior third or less of each upper
lip white; dark spot posterior to each angle of mouth uniformly
present and of large size; tip of tail black; remainder of upper
parts near (14 _l_) Sudan Brown and tone 4 of Raw Umber of
Oberthür and Dauthenay, pl. 301; occasionally, slightly darker
brown on forehead, nose, and about eyes. Underparts near (_a_ to
_c_) Ochraceous-Buff and sometimes Orange-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. Least width of color of
underparts averaging, in a series of 5 males from Mendocino
County, 57 (46-67) per cent of greatest width of color of upper
parts; 38 (35-40) in 3 males from Point Reyes, Marin County. Black
tip of tail in Mendocino County series averaging 53 (46-60) mm.,
which is same length as hind foot and 32 per cent of length of
tail. In Point Reyes males, black tip of tail averages 44 (34-52)
mm., which is less than length of hind foot and 45 per cent as
long as tail-vertebrae.