EVOTOMYS 



623 



regret to say, not one of these most interesting specimens has been 

 pi-eserved in the condition in which I received it. Some of the 

 vertebne, however, are still connected together by the dried remains 

 of the ligaments. This, and the whiteness and excellent preservation 

 of the bones, will show how easy it was to be deceived as to their 

 natiire, and to come to the belief that they were of recent origin and 

 perhaps unimportant . . . The present skulls resemble those of recent 

 Lemmings very closely indeed...! cannot find any characters 

 sufficiently important to enable me to separate the two specifically " 

 (Proc. Zool. Soc. London, 1896, pp. 304-305). Three years later, 

 however, they were examined by Nehring and distinguished from the 

 Norway Lemming as Myodes Icmmus crassidens, principally on 

 account of their relatively large molar teeth and certain fancied 

 peculiarities in the form of the coronoid process of the mandible 

 (Wiegmann's Archiv fiir Naturgeschichte, lvi, i, p. 174, June, 1899). 



Through the courtesy of the authorities of the Cambridge Museum 

 I have been able to compare the original crassidens material with a 

 series of seventeen skulls of true Icmmus in the British Museum. As 

 submitted to me this material consisted of three perfect skulls 

 (including the type), one skull without lower jaw, one rostral portion 

 of skull together with palate and maxillary teeth, two complete lower 

 jaws, and one single mandible, the whole representing not less than 

 six nor more than eight individuals. The specimens are well 

 preserved, with most of the teeth in place, and have all the 

 appearance of fresh material. In size and form the skulls show no 

 peculiarities. No old individuals are represented ; the measurements 

 therefore do not attain the maximum (s'ee Table opposite). The 

 coronoid processes are broken at the tip, giving them the short, 

 blunt appearance noted by Nehring. In one complete skull and the 

 odd mandible the teeth are of the same size as in ordinary average 

 specimens of true lemmus ; in the type they equal those of the 

 largest-toothed Norwegian specimen in the series (from Molmeu, 

 northern Gudbrandsdal) ; in one complete skull, one skull without 

 lower jaw, and one odd lower jaw they are slightly above the 

 maximum of lemmus ; while in the fragmentary skull and two odd 

 jaws they are decidedly above the maximum. That is, assuming 

 that eight individuals are represented, three are perfectly matched 

 among the seventeen Scandinavian specimens, while five are not. 

 This makes it impossible at present to synonymize crassidens with 

 Icmmus. On the other hand, it seems almost equally impossible to 

 believe that the specimens came from Portugal, and that some 

 confusion of material did not take place during the period when 

 Dr. Gadow's Athouguia mummies, regarded as "unimportant," were 

 "put aside." 



Genus EVOTOMYS Coues. 



1839. Myodes de Selys-Longchamps, Etudes de Micromamm., p. 87 



(section). 



1840. Hypudxxis Keyserling and Blasius, Wirbelth. Europas, p. 34 (sub- 



genus : type Mas glarcohis Schreber), not Hypiuhnis Uliger, 1811. 

 1858. Hypiidxus Blasius, Siiugethiere Deutschlands, p. 336 (sub-genus). 

 1874. Evotomys Coues, Proc. Acad. Nat. Sci. Philadelphia, p. 186 (genus, 



type Mus rutilus Pallas). 

 1896. Evotomys MiUer, North Amer. Fauna, No. 12, p. 42, July 23, 1896. 



