42 NORTH AMERICAN FAUNA. [no. 19. 



Lutreola vison ingens sul)sp. nov. Alaskji Mink. 



Type (skull) from Fort Yukon, Alanka. No. G530, U. S. Nat. Mu.s., $ ad., old. 

 Collected by Robert Kennicott. (See Plate VI, fig. 2.) 



Characters. — Size largest of North American mink; similar to L. v. 

 energumenos^ but lighter in color and very much larger; skull and teeth 

 v^ery large and heavy. 



Color. — Similar in general to Lutreola v. energumeno^., but palci-. 



Skull. — Very large, angular, and ridged; rostrum very wide; brain- 

 case relatively sliallow and very wide; zygomata heavy; audital ])ulhe 

 large and relatively wide; dentition heavy. (Compare with skull of 

 Lutreola v. en^rgunienos, Plate VI, fig. 1.^) 



Measurements. — No. 13880, U. S. National Museum, St. Michael, 

 Alaska (from dry skin): Total length 720; tail vertebras 180; hind 

 foot 75. Skull of type: Occipitonasal length 69; zygomatic breadth 47; 

 mastoid breadth 41; ])readth across postorbital processes 23; length 

 of audital bulla 17. Average of five adults: Occipitonasal length 

 44.5; mastoid breadth 39.5; breadth across postorbital processes 21; 

 length of audital bulla 17.5. 



LteinavTis. — The large size of the Alaska mink has been noted by 

 various authors,^ but each has dismissed the subject by concluding 

 that it is the natural result of the animal's northern range, and the 

 form has remained unnamed, while less marked forms from other local- 

 ities have been recognized. The largest mink previous!}^ described 

 is L. V. en^ergumenos, which is very much smaller than rngen.^ and also 

 averages much darker. 



The minks of the Yukon region are caught mostly on the tributarj^ 

 streams, and, as stated by Nelson, are very abundant in the area 

 between the deltas of the Yukon and the Kuskokwim. Along the 

 Yukon itself our party did not see any, and very few signs of them 

 were observed. Their skins were seldom seen among the Indians and 

 Eskimos. They were reported, however, from the Porcupine, Koyu- 

 kuk, Tanana, and various other streams tributary to the Yukon, and 

 without doubt occur in suitable places all over Alaska. 



Putorius arcticus Merriam. Tundra Weasel. 



Puioriuii arcticus Merriam, N. Am. Fauna No. 11, 15, June, 1896. 

 Putorius cicognani richardsoni Merriam, L c, 11-12 (part). 



Three immature specimens of this weasel were taken at St. Michael. 

 They were caught in traps baited with sandpipers and set among the 

 lava rocks along the shore. Several specimens which were also secured 

 at St. Michael by Nelson and Turner are in the National Museum. 

 Besides these I find specimens from Nulato, Fort Yukon, and Fort 

 Reliance, which gives the species a more extensive range in the interior 

 than it has been supposed to have. Most of these specimens are 



^ No. 5537, Bangs collection, from Sumas, B. C. 



■' See Allen, Bull. U. S. Geol. and Geog. Survey Terr., II, 327-328, 1876. 



