492 RODENTIA 
Guinea-Pig-like animals, inhabiting chiefly the mountainous parts of 
Northern Asia (from 11,000 to 14,000 feet), one species only being 
known from South-East Europe, and another from the Rocky 
Mountains. 
The Picas, or Tailless Hares, live in holes among the rocks of 
their native mountains, and are agile and shy little creatures. 
The genus is well represented through the upper and middle 
Tertiaries. It has been proposed to separate those fossil forms 
with p 2 as Myolagus, and those with p 3 as Titanomys, but this 
seems scarcely advisable. 
Family LEPORIDZ. 
Imperfect clavicles, elongated hind limbs, short recurved tail, 
and long ears. Skull 
(Fig. 216) com- 
pressed, frontals 
with large wing- 
shaped post-orbital 
processes p23; molars 
as in the Lagomyide. 
Cosmopolitan (ex- 
cept Australasia). 
Vertebre: C 7, D 
12,L 7,5 4, C 13- 
15. 
Lepus. — The 
single genus Lepus 
includes about 
twenty species, all 
of which resemble 
one another in 
general external characters. In all the fore limbs have five and 
the hind only four digits, and the soles of the feet are densely 
clothed with hairs similar to those covering the legs; the inner 
surface of the cheeks is also hairy. Although the family has such 
a wide distribution, the greater number of the species are restricted 
to the Palzarctic and Nearctie regions, only a single species (L. 
brasiliensis) extending into South America, where it has existed 
since the date of the Pleistocene deposits of the Brazilian -caves. 
The Common Hare (L. timidus*) may be taken as a typical 
example of the genus, and is characterised by the great length of 
1 Linn. Syst, Nat. 12th ed. vol. i. p. 77 (1766). 
? From the absence of the Common Hare in Scandinavia it is considered 
probable that the name Z, timidus was really applied to the Mountain Hare, 
and some writers accordingly use the name ZL. ewropeus for the former. 
Fic, 216,—Skull of Hare (Lepus timidus). 
