154 MICROTIN^ 



from the fact that Middendoi-flf, thoroughly acquainted with the 

 Old World species, thought Audubon's very fair figure of a 

 specimen of D. richardsoni in summer pelage to be " completely 

 erroneous " and " not at all to be recognized." 



3c. Dicrostonyx rubricatus unalascensis Merriam. 



1853. Myodes torquatus Middendorff, Sibir. Reise, 2, Th. 2, p. 92. Not 

 of Pallas, 1779. 



1900. Dicrostonyx unalascensis Merriam, Proc. Washington Acad. Sci., 

 2, p. 25; Miller, "List," 1912, p. 208. 



1901. Dicrostonyx hudsonius unalascensis Elliot, Field Columbian 

 Mils. Publ., Zool. Ser. 2, p. 210. 



1919. Dicrostonyx rubricatus unalascensis G. M. Allen, Bull. Mus. 

 Comp. Zool., Cambridge, 62, p. 530; Miller, " List," 1924, p. 398. 



Type.— U.S. Nat. Mus., No. 99,622 (Biol. Surv. Coll.) ; skull 

 lacking occiput, found in an owl pellet, July 8, 1899, by C. H. 

 Merriam. 



Type locality. — Island of Unalaska, Alaska. 



Range. — Known only from the type locality. 



Characters. — " Closely related to rubricatus, from which it 

 differs in its relatively longer and more slender rostrum, its 

 weaker, less broadly rounded zygomata, and slightly more pro- 

 truding incisors. External characters unknown " (G. M. Allen, 

 1919, p. 531). 



For cranial measurements, see table at end of volume. 



Remarks. — This lemming was first discovered by Wosnessensky 

 about 1850. He obtained a specimen which was examined by 

 Middendorff, who says of it : — " Es istein halbwuchsiges Weibchen 

 in der Tracht der Jungen von Taimyr, von denen es ununter- 

 scheidbar ist. Am llten Mai gefangen, zeigt es an der zweiten 

 Zehe der Vorderpfote (von innen gerechuet) die hufartige Ent- 

 wickelung des Nagels." Unalaska, situated as it is in the Pacific 

 off the extremity of the Alaskan Peninsula in lat. 54° N., has a 

 mild climate ; and the presence upon it of a member of a genus 

 otherwise restricted, so far as its hving representatives are 

 concerned, to the desolate Arctic tundra is a fact of very great 

 interest and one which should inspire caution in the geologist 

 drawing inferences as to past climatic conditions from the occur- 

 rence of remains of Dicrostonyx in the Pleistocene deposits of 

 Western Europe. For many years Wosnessensky's discovery, 

 recorded by Middendorff and by Hensel, was doubted (Nehring, 

 Ueber Tundren und Steppen, 1890, p. 23) ; but it has now been 

 fully confirmed by the U.S. Biological Survey. Curiously, 

 although twenty-nine skulls, collected from owls' pellets, have 

 now been obtained from the island, the survey has not succeeded 

 in procuring a specimen in the flesh; and our knowledge of the 

 outward appearance of the animal is limited to the statement of 

 Middendorff cited above. 



