454 ZOOLOGY SECT, 



three in the hind-foot (the hallux being absent and the fifth digit 

 vestigial). The ungual phalanges of the four complete digits of 

 the fore-foot are small, somewhat conical and flattened ; that of 

 the second digit of the hind-foot is deeply cleft, and has a long- 

 curved claw ; the rest of the digits of the hind-foot have broad 

 nails. There are no canines, and in the upper jaw there is only a 

 single pair of incisors, which resemble those of the Rodents in 

 their elongated curved form and in growing from persistent pulps. 

 The thoracic and lumbar vertebras are very numerous (28-30), 

 twenty-one or twenty-two bearing ribs. The tail is very short. 

 Clavicles are absent. There is a centrale in the carpus. The 

 stomach is divided into two parts by a constriction. The 

 large intestine has connected with it a pair of large supple- 

 mentary cceca. There is no gall-bladder. The testes do not 

 descend into a scrotum. There are six teats, four in the groin 

 and two in the axillae. The villi surround the placenta in a broad 

 band (zonaiy placenta). 



This sub-order includes only a single family, the Hyracidce, 

 with two genera, Hyrax and Dendrohyrax. 



Sub-order I. Proboscidea. 



Large Subungulata with greatly thickened integument scantily 

 furnished with hair, with massive limbs, each having five com- 

 plete digits united by skin, but each terminating in a distinct hoof: 

 and with the nose produced into a long flexible and prehensile 

 proboscis or trunk, at the end of which the external nares are 

 situated. In existing' forms only a single pair of incisors is 

 present, situated in the upper jaw, and developed into enormous 

 tusks. There are no canines, and the molars are large and 

 transversely ridged. The stomach is simple. The testes do not 

 descend into a scrotum. There are two teats, situated on the thorax. 

 The uterus is two-horned, the placenta non-deciduate and zonary. 



This sub-order includes only the Elephants (Elephas), the Mam- 

 moths, Mastodons, and other extinct forms. 



Sub-order c. Pyr other ia. 



A group of South American Tertiary hoofed Mammals com- 

 prising a single genus Pyrotheriurn of doubtful affinities, per- 

 haps allied to the Proboscidea. The teeth resemble those of the 

 extinct Proboscidean Dinotherium. 



Sxb-ordcr d. A 



m 



Extinct Subungulata with plantigrade limbs, each provided 

 with five short digits having broad terminal phalanges. A third 

 trochanter is sometimes present, sometimes absent. Carpal and 

 tarsal bones interlock to some extent, and the fibula articulates 



