440 ZOOLOGY. 



hind ones, all of tliem terminated by a very small, thin, and rounded hoof, 

 except the internal posterior, which is armed with a hooked and oblique 

 nail ; the upper lip is cleft ; the snout and ears are short ; the body densely 

 covered with hair ; and the tail reduced to a mere tubercle. One species 

 inhabits the Cape of Good Hope ; another, H. syriacus {pi. Ill, Jig. 2), is 

 peculiar to Asia. 



Fam, 7. SuiD^. In the actual fauna, this familj^ is characterized by a 

 fluctuation in the proportional numbers of the teeth, and by four toes to 

 each foot, by which it differs at once from Anoplotheridee, with which it 

 would seem to bear some affinity. The number of the molars varies from 

 three to seven ; the canines are always distinctly developed ; and the 

 incisors may either be absent, or six and less may exist, situated more or 

 less horizontally in the jaw. The two central toes alone touch the bottom 

 with their three-sided pyramidal hoof; the other toes are much developed, 

 as posterior claws provided with hoofs. The nasal bones elongate forward, 

 and terminate by a proboscis-like nose, fitted for digging. The structure of 

 the skeleton is more clumsy than in Anoplotherium, from which the Suidae 

 are always distinguished by a shorter stature. The living genera of this 

 family contain but four species, and are distributed all over the surface of 

 the globe, within the temperate and torrid zones. 



The genus Adapis, from the oldest tertiary beds, is considered by some 

 as belonging to Anoplotheridoe, by others to Suidie. There are four sharp 

 and oblique incisors above, and four below ; behind these, and on each side, 

 a stout and prominent canine, straight in the upper jaw, oblique and curved 

 forwards in the lower ; the upper molars, seven in number, are variable in 

 form, as also the lower ones, the number of which could not be ascertained, 

 from want of complete jaws. We know but one single species of this genus 

 {A. imrisiemis).! from the eocene of Montmartre. 



The genus Hyotherium is not yet sufficiently characterized. Its remains 

 were found in Central Europe, and indicate an animal of the suiline family, 

 resembling very much the babiroussa now living in the Indian Archipelago. 

 The number of the incisors is not known ; the molars, it is supposed, were 

 six on each side of each jaw. Five species are already described, one of 

 which had first been referred to the following genus. 



The genus Cho;rop)otamus^ therefore, must have some close affinities with 

 Hj^otherium, from which it differs in the structure of the molars. There 

 are on each side seven above, and six below, of these teeth, intermediate 

 between those of the peccaries and hippopotamus. Several species have been 

 distinguished ; one from Paris, another from Switzerland, and a third from 

 Spain, Un described fragments are known from the south of France and 

 Turkey. 



The genus Protochceriis appears to be an American form; as the only 

 species known was found in Illinois, The canines resemble those of 

 Choeropotamus, but differ from it in having no accessory tubercles on the 

 molars. 



The genus UyracotJiermm, from the London clay (eocene), is very nearly 

 allied to Choeropotamus, by its dentition. The four anterior molars are 

 644 



