1901.] A NEW HEDGEHOG. 285 



than that of E. auritus, and this depends on the circumstance that 

 in the last-named species the ends of the spines are brown, whereas 

 in the former the ends of the spines are wholly white. The 

 dusky bases of the spines are broader, and the space between the 

 latter and the black baud is not white as in E. auritus, but light- 

 grey. The upper part of the head, the ears, and the lateral line 

 on the margin which separates the spiny surface from the fur 

 are, as in E. auritus, brown. The upper surface of the foot has 

 a brownish tinge. The whole underside is white ; claws white. 

 The ears are comparatively larger ; the snout more acuminate. 



The callosities on the under surface of the fore and hind 

 extremities are sharply defined and deeply separated. The spines 

 attain a length of 20 mm., and have from 16 to 17 finely tubercu- 

 lated low longitudinal ridges. 



The skull bears great resemblance to the skull of E. alhulus. 

 The relation of the greatest zygomatic breadth to the basal length 

 of the skull is 1 : 1"6, as in E. alhulus ; whereas in E. auritus it is 

 sometimes, and that only in very young specimens, 1 : 1*5 ; in 

 full-grown animals it is always 1 : 1-4. The other ])eculiarities 

 presented by the skull are shown at the end of this article, in the 

 table of measurements (p. 290). 



Measurements. , 



a. 0. c. 



$ senior. 5 adult. (^ adult. 



mm. mm. mm. 



From snout to vent 160 143 142 



From vent to tip of tail 25 26-5 16 



From snout to external meatus . . 37 39 41 



From snout to the middle of the 



eye 26 2% 25 



Length of hind-foot with claws .34 36 33-5 



It seems therefore that within the boundaries of European 

 Eussia and of the western part of her Asiatic possessions there 

 are not less than six species of Erinaceus. 



As there is but little to be found about the Eussian Hedge- 

 hogs in existing literature, and as our information of their geo- 

 graphical distribution is very scanty and, for the greater part, 

 erroneous, I will give here a brief revision of the species, following 

 the classification adopted by the late Dr. J. Anderson (P. Z. S. 

 1895, p. 414). 



A. The pterygoid fossae are well developed and the pterygoids 



do not contribute to the enlargement of the auditory 



chamber. 



a. Postgienoid process of the squamosal solid and much 



smaller than the mastoid. A narrow tract, bare of spines, 



on the middle of the head. 



1. Erinaceus eueop^us L. 



Erinaceus europceus,'Lmnseus,'8yst.'Na,i. -p. 15 (1766); Pallas, 

 Zoogr. Eosso-Asiat. i. p. 137 (1811) ; Eversmann, Nat. Hist. 



