LEPUS. 121 



Lepns nigricaudatus, Bennett P^Z. S., p. 41 (1833). 



Lepus texianus, Waterhouse Nat. Hist. Mamm., ii, p. 136 (1848). 



The Jackass Hare. 



Distribution.— Southern parts of the United States and Mexico 

 to the isthmus of Tehuantepec. 



a. Skin Nuces Valley, Texas, 2-84 J. H. Gamier [Ex.] 



Order UNGULATA. 



Placental Mammals with no clavicles ; with limbs for progres-i 

 sion only ; the ist digits of all recent forms wanting; ungual pha- 

 langes hoofed ; metacarpals and metatarsals vertically elongat- 

 ed or sharply inclined ; teeth covered with enamel and molars 

 generally complex. 



Key of the Indian Genera. 



Digits of manus and pes equal or even in number ; the 3rd 

 digit of each foot asymmetrical in itself, but forms with the 

 4th digit a symmetrical pair; no 3rd trochanter to the femur, 

 posterior premolars smaller and simpler than the molars ; 

 stomach complex ; caecum small ; horns when present paired. 



[=Artiodactyla.] 



I. Ulna and iibula incomplete, coniluent with radius and tibia, 

 manus and pes functionally didactyle ; incisors rarely pre- 

 sent in the upper jaw ; lower canines incisiform ; premolars 

 and molars with uni- or bicrescentic ridges ; stomach 

 complex, four-chambered and ruminating. 



[=Selenodontia.] 



c. Horns generally present ; the third and fourth metacarpals 

 and tarsals fused to form a cannon bone ; digits two and 

 five, incomplete and wanting. [=Cotylophora.] 



d. Horns hollow and persistent; digits two and five repre- 

 sented by hoofs only ; no upper canines ; gall bladder 

 present. [=Bovidae, see key below.] 



d?. Horns solid and deciduous ; digits two and five have 

 distinct metacarpals and phalanges ; no gall bladder. 



[=Cervidae.] 



e. Horns small ; upper canines well-developed ; distal 

 tarsal elements all united except an ectocuneiform. 



Cervulus, p. 172. 



