io8 CHARACTERS OF VERTEBRATE ANIMALS 



of this huge lumbering creature, which weighs about 2^ tons, 

 suggests a parody on the pig, or a large barrel mounted on four 

 stout ungainly legs. Each foot possesses four toes provided with 

 rounded hoofs. The head is enormous, and 

 the snout greatly swollen. The thick skin is 

 almost devoid of hair, and is thrown into folds 

 above the limbs. Those who have noticed a 

 captive hippo open its tremendously wide mouth 

 will have seen a truly terrific dentition dis- 

 played. Above are two peg-like incisors flanked 

 by large canines, while below there are two 

 huge cylindrical incisors, two smaller incisors, 

 and formidable tusk-like canines (fig. 74). A 

 f full complement of grinding teeth is present, 

 , The cheek teeth, origin- an d the lar^c molars, when their crowns are 



ally tubercled, but worn down 



by use so as to present the worn, exhibit Si pattern resembling a double 



appearance of clover-leaves 



bordered by bands of enamel; trefoil. The hippOpOtamUS WaS Well knOWn tO 



z, incisors; c, canines. - . i i i 1 i r <~- 



the ancients, and is the behemoth of Scripture. 



2. The Pig Family has a wide distribution both in the Old 

 and the New World. Well-marked features are the bristly skin, 

 flexible snout tipped by a fleshy disc within which the nostrils 

 open, teats extending right along the under side of the body, and 

 legs of moderate length and thickness. There are four toes on 

 each foot, the two central ones only reaching the ground, and 

 being of relatively large size. The most illustrative type is the 

 Wild Boar (Sits scrofa), once a native of Britain, and which at 

 the present time ranges throughout Europe, Asia, and North 

 Africa. It appears to be the original stock from which the 

 domestic pig has been derived. The teeth are numerous and of 

 primitive type, the points of greatest interest being the tusk-like 

 canines, all four of which are upwardly directed, and the grinding 

 teeth, which possess tuberculated crowns. 



In Africa south of the Sahara the Wild Boar type is replaced 

 by forms in which there are swellings on the face caused by 

 underlying bony projections. These are comparatively small in 

 the Red River- Hog (Potamochcerus penicillatus] of Guinea, which 

 is further distinguished by a tuft of hair at the tip of each ear; 

 but in the Wart-Hogs they are of large size, and give the enor- 

 mous head a particularly forbidding appearance. There are two 

 species, one (Phacochozrus SEthiopicus) being found at the Cape, 



