Part 15

=Michigan.= _Isle Royal_: Tobin Harbor, 1[76]; Bell Isle, 1[76]; Washington Harbor, 3[76]. _Ontonagon County_: Ontonagon, 2 (1[76], 1[14]); T. 51N, R. 43W, S. 17, Porcupine Mts., 1[76]. _Gogebic County_: Little Girls Point, 5[76]; Ironwood, 1[76]. _Iron County_: no locality more definite than county, 1[76]. _Luce County_: Tahquamenon River Falls, 1[91]. _Chippewa County_: Sault Ste. Marie, 2[76]. _Emmet County_: Wilderness State Park, 2[76]. _Cheboygan County_: Univ. Mich. Biol. Station, 1[76]. _Washtenaw County_: Ann Arbor, 1[76].

=Minnesota.= _Kittson County_: no locality more definite than county, 1[2]. _Roseau County_: Deer Township, 1[14]; Falun Township, 2[14]. _Marshall County_?: Moose River, 5[93]; Warren, definitely in Marshall County, 1[93]. _Cook County_: Grand Marais, 3 (2[76], 1[14]). _St. Louis County_: 2 mi E Babbitt, 14[93]; Burntside [= Burnside] Lake, 1[91]. _Itasca County_: T. 61N, R. 26W, 23. _Clay County_: Moorhead, 3[9]. _Aitkin County_: Aitkin, 13 (11[60], 1[7], 1[4]). _Otter Tail County_: Arthur, 3[60]; Ten Mile Lake, 1[76]; Parkers Prairie, 2[75]. _Chisago County_: North Branch, 1[60]. _Sherburne County_: Elk River, 42 (16[91], 5[14], 20[59], 1[74]). _Hennepin County_: Lake Minnetonka, 1[75]; Minneapolis, 1[91]; Fort Snelling, 5 (4[2], 1[60]).

=North Dakota.= _Pembina County_: Walhalla, 1[91]. _Nelson County_: Stump Lake, 1[91]. _Eddy County_: Brantford, 2[76].

=Wisconsin.= _Douglas County_: T. 44N, R. 13W, 1; Gordon, 1. _Bayfield County_: Brinks Camp, Washburn, 1[2]; "near Cable," 1. _Ashland County_: Bear Lake, 2. _Iron County_: Fisher Lake, 4; Mercer, 5. _Vilas County_: Mamie Lake, 16[91]; Ox Bow Lake, 1[91]. _Oneida County_: Tomahawk Lake, 1[60]. _Langlade County_: T. 34N, R. 11E, 3. _Rush County_: Ladysmith, 1. _Dunn County_: Colfax, 2. _Door County_: Mink River, Ellison Bay, 1[76]. _Dodge County_: Fox Lake, 1[50]; Beaver Dam, 12[50].

=Mustela erminea invicta= Hall

Ermine

Plates 2, 3, 4, 9, 10, 11 and 41

_Mustela erminea invicta_ Hall, Journ. Mamm., 26:75, February 27, 1945; Hall, Journ. Mamm., 26:180, July 19, 1945.

_Putorius cicognanii_, Preble, N. Amer. Fauna, 27:230, October 26, 1908.

_Type._--Male, subadult, skull and skin; no. 101122, Mus. Vert. Zoöl.; Benewah, Benewah County, Idaho; October 24, 1926; obtained by William T. Shaw.

The skull has a hole in the right squamosal bone on the floor of the braincase, and lacks the hamular process of the left pterygoid. The postmolar part of the right lower jaw is missing. The teeth all are present and entire. The skin is in white, winter pelage, well made, and in a good state of preservation.

_Range._--Central Rocky Mountain region from Jasper Park south over Alberta, southeastern British Columbia, Washington east of the Cascades, and north and central Idaho and northwestern Montana. See figure 25 on page 95.

_Characters for ready recognition._--Differs from _M. e. richardsonii_, in males, by skull lighter than 1.9 grams, mastoid breadth less than 19.9, depth of skull at anterior margin of basioccipital less than 12.4, in females by corresponding measurement of depth less than 10.1, and weight of skull less than one gram; from _M. e. fallenda_, in both sexes, by upper lips white (not brown), in males by skull averaging longer (37.0 versus 35.7), in females by breadth of rostrum less, instead of more, than 30 per cent of basilar length; from _M. e. streatori_, _gulosa_, and _muricus_ by hind foot more than 36 and basilar length more than 35 in males and by hind foot more than 29.5 and basilar length more than 30.5 in females; further distinguished from _streatori_ by white (not brown) upper lips and from _gulosa_ by black tip of tail more than half length of tail-vertebrae.

_Description._--_Size._--Male: Ten adults and subadults from central Idaho County yield average and extreme measurements as follows: Total length, 291 (272-328); length of tail, 86 (75-100); length of hind foot, 39.9 (38-44).

Female: Five adults and subadults from the same locality yield average and extreme measurements as follows: Total length, 255 (245-270); length of tail, 71 (68-76); length of hind foot, 32.3 (32-33).

_Color._--As described in _Mustela erminea richardsonii_ except that underparts in summer Marguerite Yellow or more whitish; least width of color of underparts averaging, in four females from Idaho and Montana, 38 (33-43) per cent of greatest width of color of upper parts. Black tip of tail in same specimens 38 (31-42) mm. which is 57 (52-65) per cent of length of tail-vertebrae.

_Skull._--Male (5 adults from Idaho County): See measurements and plates 2-4. As described in _Mustela erminea richardsonii_ except that: Weight, 1.5 (1.4-1.7) grams; basilar length, 37.0 (35.8-39.8).

Female (illustrated by adult and 4 subadults in table of cranial measurements, which see): See plates 9-11. As described in _Mustela erminea richardsonii_ except that: Weight, 0.72 (0.7-0.9) grams; basilar length, 32.2 (31.6-32.8).

From _fallenda_, _invicta_ differs in that the skull of the male has a relatively narrower rostrum and relatively shallower braincase. Females show the same differences but the degree of difference is about as great again as in males. The teeth are almost exactly the same size in the two subspecies. The weight is the same in males but in females _invicta_ is 18 per cent heavier.

From _streatori_, _invicta_ differs in that males average larger in every measurement taken except that the anteroposterior diameter of the inner moiety of M1 is less; 36 per cent heavier; linear measurements of the skull are about 5 per cent larger and those of the teeth, with the one exception noted, about 6 per cent larger; relative to the basilar length the tympanic bullae are longer and the rostrum is relatively narrower. In females, measurements of the skull average 8 per cent more and those of the teeth 7 per cent more except that, as in males, the inner lobe of M1 is actually shorter. Females of _invicta_ are 12 per cent heavier; relative to the basilar length the skull is narrower throughout and the tooth-rows are shorter than in _streatori_.

From _gulosa_, _invicta_ differs in that males average larger (about 12 per cent) in every measurement taken, excepting the anteroposterior diameter of M1 which is the same; 50 per cent heavier; relative to the basilar length the length of the tooth-rows and interorbital breadth are less. In females the inner lobe of M1 is smaller but every other measurement taken of the skull and teeth is more, _invicta_ averaging about 8 per cent larger and 22 per cent heavier; relative to the basilar length, the tooth-rows are shorter and the skull is narrower interorbitally, through the rostrum and across the zygomata.

From _murica_, _invicta_ of corresponding sex differs in being larger in every measurement taken; males average 17 per cent larger in cranial measurements, 13 per cent larger in dental measurements and are 83 per cent heavier; corresponding percentages for females are 11, 9 and 20. Exception must again be made for the anteroposterior diameter of the inner lobe of the last upper molar which is less in females, and only slightly more in males. In males of _invicta_ the tympanic bullae are longer in relation to the basilar length.

From the geographically remote _cicognanii_, skulls of both males and females of _invicta_ are to me individually indistinguishable. There is, nevertheless, an average difference not apparent to the eye between skulls of males. If the length of the tooth-rows be taken as a standard (100 per cent), the rostrum, of _invicta_, as measured across the lacrimal processes is broader (89 rather than 84 per cent) but the width across the fourth upper premolars is less, 94 rather than 97 per cent of the length of the tooth-rows.

Since the skull of _invicta_ closely resembles that of _cicognanii_, it follows that _invicta_ differs from _richardsonii_ and _bangsi_ in about the manner described in the account of _cicognanii_.

_Remarks._--Animals of this subspecies in advance of the present study generally were recorded in the literature under the name _Mustela cicognanii_. The difficulty in distinguishing individual specimens of _invicta_ on morphological grounds from those of the geographically remote _M. e. cicognanii_ should not be taken to indicate that the populations do not differ appreciably. Actually they differ in several characters although in no one of these is the degree of difference sufficient to allow of using it alone as a certain means of diagnosis. In _invicta_, as compared with _cicognanii_, the light-colored underparts are wider in relation to the dark-colored upper parts and the tail is longer by 4 per cent relative to the head and body. Given a population of each of the two subspecies, in which the skull is of the same mass, the hind feet are longer in _invicta_, there is more sexual dimorphism in size, and the anterior part of the skull differs in some particulars as just described in the comparison of the skull of _invicta_ with other forms. Nevertheless, each of these differences is of an average sort. Therefore, and because overall size is about the same in the two subspecies concerned, one or a few specimens from, say, central Idaho, can be distinguished from animals from western Pennsylvania only with difficulty, if at all. The close resemblance of skulls of _invicta_ and _cicognanii_ may be a function of their living at approximately the same latitudinal position in a climate that has marked seasonal variation.

Intergradation with _richardsonii_ is complete and gradual; in one sense _invicta_ is but little more than a small _richardsonii_. Intergradation with _fallenda_ is shown by several specimens. These two races differ in large degree in color, and in size and shape of the skull of females. Although the geographic area where intergradation in color occurs is fairly wide, the area in which intergradation in cranial characters in females occurs, appears, from the inadequate material available, to be much narrower. Intergradation occurs freely in Washington with _streatori_ but with _muricus_ so far as known only in the Bitterroot and nearby mountains of northwestern Montana. The Snake River Plains and low country along much of the Columbia River appears to be uninhabited by weasels of the species _erminea_ and hence there is opportunity for intergradation only in the mentioned area of Montana.

_Specimens examined._--Total number, 177, as follows. Arranged alphabetically by provinces and states then by localities from north to south in each province and by counties from north to south in each state. Unless otherwise indicated, specimens are in the United States National Museum.

=Alberta.= Jasper House, 4[77]; Shovel Pass, 2[77]; Jasper Park, 10[77]; head of Smoky River, 9; Henry House, 2 (1[77]); Blindman River, 1[2]; forks of Blindman River and Red Deer River, 2 (1[60], 1[75]); "near Red Deer, Red Deer River," 1[77]; Red Deer River, 2 (1[2], 1[60]); Red Deer, 2[60]; Rosebud, 2[77]; Prairie, 3000 ft., 1; Didsbury, Little Red Deer River, 1; Canadian Nat'l Park, 1[60]; Canmore, 1; Banff, 1[60]; High River, 1[86]; "Waterton Lake Park" in Alberta, 6[77].

=British Columbia.= Grand Forks of Fraser River, 1; Canoe River, 1[77]; Field, 1; Glacier, 1[58]; E side Beaverfoot Range, 4000-4500 ft., 6 mi. SE Fraser Creek, 8[74]; Wentworth Lake, 1[31]; Revelstoke, 2 (1[77], 1[60]); Spillimacheen[e]en River, 2[2]; Sicamous, 2; Albert River, 7000 ft., 1[2]; Lumby, Creighton Valley, 1[31]; Okanagan, 4 (2[75], 1[94], 1[2]); Kettle River Lake, Gold Range, 4000 ft., 1; Crows Nest Station, 1[74]; Yale District, 3; Fort Hope, 1; Chilliwack Lake, 1[77]; Skagit, 2 (1[77], 1[31]); Skagit Valley, 1[77]; Skagit Summit, 1[77]; Lightning Lakes, 2 mi. N International Boundary, 3; Osoyoos-Bridesville Summit, 2; Westbridge, 1[77]; Rossland, 5[77]; Creston, mouth Goat Creek, 3[77]; Yahk, 4[77].

=Idaho.= _Bonner County_: Coolin, 4. _Benewah County_: Benewah, 1[55]. _Idaho County_: "Pete Kings, Lochsa River," 1[97]; 2 mi. SSE Selway Falls, 1900 ft., 1[8]; 4 mi. SW Selway Falls, 5800 ft., 3[8]; Newsome Cr., 12 mi. above jct. with S Fk. Clearwater River, 2[74]; Iron Mt., to 14 mi. W thereof, 24[74]; Pilot Cr., 3/4 to 2-1/2 mi. above Newsome Cr., 4[74]; Sawmill Cr., 1-1/4 mi. W Newsome, 1[74]; between Selway River and S. Fk. Clearwater R., 4[74].

=Montana.= _Teton County_ (of old arrangement of counties): Many Glacier, 4900 ft., 1[74]; Duck Lake, 6 mi. NE St. Marys Lake, 1; St. Marys, Glacier Park, 1[76]; Lower St. Marys Lake, 1[2]. _Flathead County_: Stanton Lake, 5. _County_ in question: Bitter Root Mts., 1. _Ravalli County_: Tin Cup District, 1[74]; Bass Creek, 6800 ft., NW of Stevensville, 1; Capitan Peak, 7000 ft., 1; Darby, 2[74]; Girds Creek, 1[74]; Charlos Heights, 2[74].

=Washington.= _Whatcom County_: Twin Lakes, Winchester Mts., 3 (1[10]); Chilliwack River, 2600 ft., 2; Cooper Creek, near head, 4500 ft., Hannegan Pass, 1; Cooper Cr., 4300 ft., Hannegan Pass, 1[10]; Beaver Creek (2500 ft., and at McMillan Ranch, 1700 ft.), 2; Barron, Bornite Mine, 5000 ft., 1. _Okanogan County_: Tungsten Mine, 6800 ft., Bauerman Ridge, 4; Hidden Lakes, 4100 ft., 1; West Fork Pasayten River, 4700 ft., 1. _Stevens County_: Orin, 1[51]. _Pend Oreille County_: Ione, 2[51]. _Chelan County_: Lake Chelan, 1[46].

=Mustela erminea alascensis= (Merriam)

Ermine

Plates 2, 3, 4, 9, 10 and 11

_Putorius richardsoni alascensis_ Merriam, N. Amer. Fauna, 11:12, pl. 2, figs. 2, 2a, June 30, 1896.

_Putorius cicognanii alascensis_, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Swarth, Univ. California Publ. Zoöl., 7:140, January 12, 1911.

_Mustela erminea alascensis_, Hall, Proc. Biol. Soc. Washington, 57:36, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

_Type._--Male, adult, skull and skin; no. 74423, U. S. Nat. Mus., Biol. Surv. Coll.; Juneau, Alaska; August 22, 1895; obtained by Clark P. Streator, original no. 4806.

The skull shows malformation of the frontal sinuses due to parasites and lacks osseous tissue where the parasitic infestation was localized. The left exoccipital condyle and adjacent region is less developed than the right and the posterior part of the skull is bent slightly to the left. Otherwise the skull is unbroken. The teeth all are present and entire. The skin is in the brown summer coat, fairly well made and in a good state of preservation. A few white hairs persist where the proximal line of the black hair of the tip of the tail meets the distal line of the brown hair.

_Range._--Mainland of southeastern Alaska from Lynn Canal south to include Mitkof, Zarembo, Wrangel and Revillagigedo islands. See figures 25, 26 on pages 95 and 134.

_Characters for ready recognition._--Differs from _M. e. arctica_ and _haidarum_, in both sexes, by proximal two-thirds of under side of tail colored same as upper parts rather than same as underparts and interorbital breadth less, instead of more, than distance between glenoid fossa and posterior border of external auditory meatus; from _M. e. salva_, in males, by overall depth of braincase including tympanic bullae less than 89 per cent of orbitonasal length, females not individually distinguishable but averaging shallower through the braincase; from _M. e. initis_, _celenda_ and _seclusa_ by interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus (females of _initis_, _celenda_ and _seclusa_ unknown); further from _initis_ by total length less than 317 and black tip of tail less than 57 per cent of length of tail-vertebrae; further from _celenda_ by chest white, not mostly covered by brown patch.

_Description._--_Size._--Male: Eight adults from Windham, Alaska, yield average and extreme measurements as follows: Total length, 298 (288-315); length of tail, 88 (84-94); length of hind foot, 41.3 (37-44).

Female: Two adults from Juneau and Helm Bay measure, respectively, as follows: Total length, 258, 258; length of tail,----, 76; length of hind foot, 32, 34.

_Color._--As described in _Mustela erminea richardsonii_ except that least width of color of underparts averaging, in five females, 42 (35-53) per cent of greatest width of color of upper parts. Black tip of tail in same specimens averaging 36 (30-40) mm. which is 49 (48-53) per cent of length of tail-vertebrae.

_Skull._--Male (based on 8 adults from Windham): See measurements and plates, 2-4. As described in _Mustela erminea richardsonii_ except that: Weight, 1.8 (1.5-2.6) grams; basilar length, 37.5 (36.5-38.9); length of tooth-rows more or less than (about same as) length of tympanic bulla.

Female (based on 5 adults, from localities listed in the table of cranial measurements): See measurements and plates 9-11. As described in _Mustela erminea richardsonii_ except that: Weight, 0.96 (0.7-1.1) grams; basilar length, 32.7 (31.9-33.2); breadth of rostrum more or less than (about equal to) 30 per cent of basilar length.

From _richardsonii_, _alascensis_ differs in that the skull of the male averages smaller in every measurement taken and is 28 per cent lighter. Relative to the basilar length, the orbitonasal length is more and the braincase is shallower as measured at the anterior end of the basioccipital. The four adult females seen of _alascensis_ are more variable than those of _richardsonii_ and average smaller in some measurements and larger in others but give no proof of any consistent difference.

From _haidarum_, _alascensis_ differs in that the rostrum and entire preorbital part of the skull is actually as well as relatively much smaller in both sexes. In males of _alascensis_ the length of the skull, and other cranial measurements of length, is more. In males, the mastoid breadth and zygomatic breadth are about the same as in _haidarum_, as also is the weight. M1 is larger but m1 and P4 are smaller. In females the anteroposterior extent of the inner moiety of M1 and length of tympanic bulla are about the same in the two subspecies but all other cranial and dental measurements in _alascensis_ are less. It is 29 per cent lighter. The difference in the preorbital region is of about the same degree as in the males.

Comparisons of the skull with those of _arctica_, _salva_, _initis_, _celenda_, and _seclusa_ are made in the accounts of those subspecies.

_Remarks._--The relatively few specimens known of this race seem always to have been referred to in the literature by the name _alascensis_ and the nomenclatural history is therefore simple. The original materials were obtained by the collector Clark P. Streator and the additional series of skeletons, one with skin, from Windham were procured by Stanton Price, a resident there.

The subspecies is well differentiated from both _arctica_ and _richardsonii_. Although actual intergrades are lacking between _alascensis_ and the two races just mentioned I have no doubt that intergradation occurs with _richardsonii_ and think it probably does also with _arctica_.

The assignment of the three females from Mitkof Island, Zarembo Island, and Loring on Revillagigedo Island, is tentative because each is so young as not to show diagnostic cranial characters. The two other specimens from Revillagigedo Island (Carroll Inlet), labeled as males, are in white winter pelage. Only one, no. 136358, a subadult, is accompanied by a skull. The small size of each specimen, and its cranial characters which are intermediate between those of males and females of _alascensis_ of the adjacent mainland, indicate the existence of a distinct race of weasel on Revillagigedo Island. On the chance that the one specimen with a skull is a dwarf, or is wrongly sexed as seems improbable, the population is tentatively referred to _alascensis_.

_Specimens examined._--Total number, 24, arranged by localities from north to south. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California.

=Alaska.= Juneau, 5[91]; Taku River, 1; Windham, 9; Mitkof Island, 1; St. John Harbor, Zarembo Island, 1; Wrangel, 1[91]; Helm Bay, Cleveland Peninsula, 1; Cleveland Peninsula, 2[91]; Revillagigedo Island, Carroll Inlet, 2[91]; Loring, 1[91].

=Mustela erminea salva= Hall

Ermine

Plates 2, 3, 4, 9, 10 and 11

_Mustela erminea salva_ Hall, Proc. Biol. Soc. Washington, 57:35, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

_Type._--Male, adult, skull only; no. 74641, Mus. Vert. Zoöl.; Mole Harbor, Admiralty Island, Alaska, December 27, 1936; obtained by A. Hasselborg.

The skull (plates 2-4) shows malformation of the frontal sinuses owing to parasites and lacks osseous tissue where the parasitic infestation was localized. The skull is unbroken. The teeth all are present and entire.

_Range._--Admiralty Island, Alaska. See figures 25, 26 on pages 95, 134.

_Characters for ready recognition_ (known only from skulls).--Differs from males of _M. e. alascensis_ in overall depth of braincase which is more than 89 per cent of orbitonasal length; from _M. e. initis_, in males, in that orbitonasal length and mastoid breadth total less than 35 mm., weight of skull and lower jaws less than 2.1 grams; from _M. e. celenda_, in males, in that breadth of rostrum measured across lacrimal processes less than a third of basilar length.

_Description._--_Size._--Male: An adult from Gambier Bay measures: Total length, 320; length of tail, 95; length of hind foot, 45 (41 in dry skin).

Female: A subadult from Hawk Inlet, measures: Total length, 250; length of tail, 70; length of hind foot, 33.

_Color._--As described in _Mustela erminea richardsonii_ except that least width of color of underparts in four individuals 40 (38-43) per cent of greatest width of color of upper parts. Black tip of tail, in two individuals for which external measurements are given, amounting to 50 and 40 mm. respectively which is 53 and 57 per cent of length of tail-vertebrae.

_Skull._--Male (type and 4 adult topotypes): See measurements and plates 2-4. As described in _Mustela erminea richardsonii_ except that: Weight, 1.7 (1.5-1.9) grams; basilar length, 37.8 (36.4-39.5, extremes are in subadults); length of tooth-rows more or less (usually more) than length of tympanic bulla; interorbital breadth rarely more than distance between glenoid fossa and posterior border of external auditory meatus.

Female (2 ad. and 1 ad.-sad. topotypes): See measurements, and plates 9-11. As described in _Mustela erminea richardsonii_ except that: Weight, 0.9 (0.8-1.0) grams; basilar length, 33.0 (32.0-33.6); length of tooth rows approximately same as length of tympanic bulla; breadth of rostrum approximately 30 per cent of basilar length.