496 



RODENTIA 



angle extending from inner face about three-quarters of distance 

 across crown, the adjacent edges of the fold closely approximated 

 and finely crenulate ; posterior section of second, third and 

 fourth lower cheek-teeth about four-fifths as wide as anterior 

 half ; last upper molar a small elliptic cylinder ; third lower 

 molar with anterior segment elliptical in section, the posterior 

 segment smaller and nearly terete, the enamel of the two 

 cylinders normally separate throughout. Externally charac- 

 terized by the soft pelage, well developed tail, and long feet 

 heavily clothed with hair that nearly conceals the nails. Young 

 at birth active, the eyes open, and the body completely furred. 



Remarks. — As now restricted the genus Lepus contains about 

 eighty named species. Eight of these occur in Europe, most of 

 them represented by several geographic forms. 



KEY TO THE EUROPEAN FORMS OF LEPUS. 



Tail, including pencil, much shorter than hind 

 foot, its upper surface white or clouded with 

 brown or grey, never with clear black median 

 area ; zygoma relatively deep anteriorly, the 

 distance from anterior termination of groove 

 on outer surface to front edge less than least 

 depth; root of upper incisor extending to 

 suture between premaxillary and maxillary ; 

 pelage usually changing to white or whitish 

 in winter (distribution northern and Alpine) 

 Varying Hares. 

 General colour of upper parts in summer dull 



russet (approaching the wood-brown and 



russet of Eidgway) ; winter pelage never 



entirely white (Ireland) ... L. hibemicus, p. 531. 



General colour of upper parts in summer greyish 



brown (approaching the broocoli-brown and 



hair-brown of Ridgway) ; winter pelage 



usually white or pale grey L. timidus,-p. 522. 



Occipitonasal length of adult skulls ranging 

 from 95 mm. to 103 mm. (Scandinavian 



Peninsula) L. t. timidw, -p. 526. 



Occipitonasal length of adult skulls ranging 

 from 85 to 93 mm. 



Ear from crown 80 to 90 mm. (Scotland) L. t. scoticus, p. 529. 



Ear from crown 90 to 100 mm. (Alps) L.t. vwronis, p. 528. 



Tail, including pencil, about as long as hind foot, 

 its upper surface with conspicuous clear 

 black median area ; zygoma relatively shallow 

 anteriorly, the distance from anterior ter- 

 mination of groove on outer surface to front 

 edge usually equal to or greater than least 

 depth ; root of upper incisor not extending to 

 suture between premaxillary and maxillary ; 

 pelage never changing to white and rarely to 

 grey in winter (distribution central and 

 southern) Ordinary Hares. 

 Hind foot less than 105 mm. ; legs without white 



markings, the inner surface scarcely lighter 



than outer (Sardinia) L.meditetranetis, p. 513. 



