282 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
external and osteological characters, though presenting many features of 
general resemblance. No subdivisions of the family can apparently be made 
having a higher than generic value, the species being, in fact, apparently all 
strictly congeneric. 
The most obvious external distinguishing characters of the Hares are 
their lengthened hind limbs, their large, sometimes very large, ears, and 
short, sometimes rudimentary, bushy, erect tail; most of the species have a 
thick coat of very soft loose fur. The skull presents also distinguishing 
features, namely, the large, deep, flattened rami of the lower jaw; the per- 
forated or reticulated condition of the facial surface of the maxilla; the large 
size of the orbits, in which the foramina are confluent; the large size of the 
anterior palatine foramina, and the reduction of the palate to a mere bridge 
between the premolars; the large size, in short, of all the openings of the 
skull; the possession of more than the usual number of teeth, including both 
molars and incisors. The dental formula is as follows :— 
ie pa C. Goals ‘Pp: duals M. ae = ne = 20. 
j—1 U-O0 2-2 3-3 «12 
The molars are rootless. Lagomys shares with Lepus the possession 
of several of these cranial characters, but they are much less developed. 
In respect to the general skeleton, besides the elongated hind legs and 
feet, the Hares have the acromion-process of the scapula provided with a 
spine (metacromion) directed posteriorly at right angles to the axis of the | 
scapula. The vertebral processes are generally long and slender, the thoracic 
vertebrae being provided with “remarkably long, single, compressed, median 
hypapophyses”, not usually present in the other Rodentia. 
GreNuS LEPUS Linn. 
Lepus Linn., Syst. Nat. 
Hydrolagus Gray, Ann. & Mag. Nat. Hist., 3d ser., xx, 221, 1867. 
Sylwilagus GRAY, ibid., 221. 
Eulagos Gray, ibid., 222. 
Lepus GRAY, ibid., 222. 
Tapeti GRAY, ibid., 224. 
Cuniculus GRAY (nec Wagler), ibid., 225. 
Oryctolagus Litt JEBORG, Fauna éfver Sveriges och Norges, 417, 1873. Type L. cuniculus Linn.; hence 
= Cuniculus Gray. 
The characters of the genus have been sufficiently indicated in the 
preceding description of the family. 
