568 



RODENTIA 



;^yg<)mata. The foi'm of the auditory bulla is also, as in Eliomys, 

 much more inflated anteriorly tlian posteriorly, and readily dis- 

 tinguishable from the rounder, more evenly inflated bulla of 6r//.s' 

 and MuscardlnuH. 



Teeth. — The detailed structure of the teeth has already been 

 sufliciently described. As compared with those of Eliomi/s 

 quercinuH the molar rows are more nearly parallel, and there is 



Fig. 111. 

 Dijromys nitedula. Nat. .size. 



FIG. 112. 

 Dijromys nitedula. Cheek-teeth. 



X 10. 



usually less contrast in size both above and below between the 

 premolar and last molar with the two middle teeth. 



Memarlxs. — Among the European Muscardinidx this species is 

 immediately recognizable by the combination of a dark face 

 streak and uniformly bushy tail. In size it is intermediate 

 between 3Inscardinus avellanarius and Eliomys quercinus, but 

 nearer the former. In different parts of its range Dyromys 

 nitedula has become modified into four local races, three of 

 which occur in Europe. 



Dyromys nitedula nitedula Pallas. 



1778. Mils nitedula Pallas, Nov. Sp. Quadr. Glir. Ord., p. 88, part, des- 

 cription, not synonymy (Region of the lower Volga, Russia). 



1782. Mijoxus dnjas Schreber, Siiugthiere, pi. ccxxv b. ; description, iv, 

 p. 831, 1787 (Region of the lower Volga, Russia). 



1857. Myoxus dryas Blasius, Siiugethiere Deutschlands, p. 295. 



1906. Eliomys nitcdulus Thomas, Proc. Zool. Soc, London, 1905, ii, p. 348, 

 April 5, 1906. 



1910. Dyromys nitedula Trouessart, Faune Mamm. d'Europe, p. 133. 



Type locality. — Region of the lower Volga, Russia. 



Geograplucal distribution. — South-eastern Europe north of 

 the Balkan Peninsula, west to Hungary. Exact limits of distri- 

 bution not known. 



