LEMMUS. 259 



Myodes alhigularis Wagn., Schreb. Saugth., Suppl., in, 1843, P- 602. 

 Lemtnus alascensis Merr., Proc. Wash. Acad. Scien., 11, 1900, p. 26. 

 Lemmus irimucronatus Elliot, Syn. N. Am. Mamm., F. C. M. Pub., 

 II, 1901, p. 207, fig. 47. Zool. Ser. 

 Richardson's Lemming. 



Type locality. Point Lake, N. Lat. 65°, Mackenzie, Canada. 

 Geogr. Distr. Arctic regions of North America. 



(t. Lcimmis triT)incrnnaiiis helroJus (Richardson). 



Arvicola (Georychtts?) helvohis Rich., Faun. Bor. Amer., Mamm., 



1829, p. 128. 

 Lemmus trimticronaius helvolus Elliot, Syn. N. Am. Mamm., 

 F. C. M. Pub., II, 1901, p. 208. Zool. Ser. 

 Yellowish Lemming. 



Type locality. Alpine swamps, Arctic America, 56° north latitude. 

 Geogr. Distr. Arctic regions of North America. 



h. Lemmus trimiicronatus yukonensis (Merriam). 



Lemmus yukonensis Merr., Proc. Wash. Acad. Scien., 11, 1900, p. 27. 



Lemmus irimucronatus yukonensis Elliot, Syn. N. Am. Mamm., 

 F. C. M. Pub., II, 1901, p. 208. Zool. Ser. 

 Yukon Lemming. 



Type locality. Charlie Creek, Yukon River, Alaska. 



Geogr. Distr. Yukon River District, Alaska. Range unknown. 



630. Lemmus minusculus Osgood. 



Lemmus minusculus Osgood, N. Am. Faun., No. 24, 1904, p. 36. 

 Small Lemming. 



Type locality. Kakhtul River near junction with the Malchatna 

 River, Alaska. 



Geogr. Distr. Alaska. Range unknown. 



Genl. Char. "Similar in general to L. alascensis (L. irimucrona- 

 tus) but much smaller." Skull with naso-frontal region elevated; 

 rostrum depressed. 



Color. Upper parts mixed ochsaceous and black, becoming light 

 chestnut on the rump ; blackish median line from nose to shoulders ; 

 lower sides and under parts ochraceous or tawny ochraceous; ears 

 dusky; hands and feet seal brown; tail sometimes uniform pale buff 

 above and below, again in other specimens blackish above, light buff 

 below. 



Measurements. Average of 10 males. Total length, 131; tail 

 vertebrae, 12; hind foot, 19. Skull: greatest length, 28.5; Hensel, 

 25.4; zygomatic width, 19; mastoid width, 15; length of nasals, 8.9; 

 postpalatal length, 12.2; length of upper molars, 8. 



