XIII PHYLUM CHORDATA 483 



supplementary cseca. 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 (zonary placenta). 



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

 with two genera, Hyrax and BendrdhyD'oxc. 



Si(h-order h. — 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 deciduate and 

 zonary. 



This sub-order includes among existing forms only the Elephants 

 {Elephas). 



Order 5. — Carnivora. 



Mainly carnivorous Eutheria with furry integument, with never 

 less than four well-developed digits in the manus and pes, all 

 provided with claws, which are frequently more or less retractile. 

 The pollex and hallux are never capable of being opposed to the 

 other digits. The clavicle is frequently absent, and, when present 

 is never complete. There is often a foramen over the inner con- 

 dyle of the humerus. The scaphoid and lunar of the carpus are 

 always united, and there is never an os centrale. 



The Carnivora are diphyodont and heterodont, and the teeth are 

 provided with roots. The incisors, usually three pairs in the upper 

 and three in the lower jaw, are small and chisel-shaped. The canines 

 are usually large, conical, curved, and pointed. The premolars and 

 molars are usually compressed and trenchant, especially the most 

 anterior. The stomach is simple ; the caecum, when present, is 

 small. The brain is usually highly developed, and the cerebral 

 hemispheres always convoluted. The teats are abdominal. The 

 uterus is two-horned ; the placenta deciduate and nearly always 

 zonary. 



Sub-order a. — Carnivora vera. 



Carnivora which have the limbs nearly always adapted for a 

 terrestrial existence, with all the digits usually provided with 

 claws, which may be retractile into a sheath. The first digit of 



