386 ON THE FOSSIL BONES OF PACHTnEKMATOrS QUADIIUPKDS, 



galus, e (fig. 19), is larger on the internal side, where the malleolus 

 forms an acute angle. 



It resembles the tibia of the ox more than that of any other animal, 

 but the latter is more elongated. The projection of the anterior edge 

 does not descend so low in the latter, and is not so flattened and so 

 slanted at the top. Tliat of the pig is also more elongated, and the 

 slopes of its upper extremity are less marked. 



The fibula, d (fig, IS), is very rough and very much separated from 

 the tibia throughout, except at the two extremities. The malleolar 

 little bone becomes instantly united to the inferior extremity. 



It is also after the model of that of the pig that the tarsus of the 

 hippopotamus is principally constructed. 



The astragalus, A (plate 3 1 , fig. 20), is larger in proportion ; as in the 

 ruminants and in the pig, its lower pully is divided into two gorges, 

 a h, separated by a blunt edge ; but these two gorges are almost equal and 

 very slightly concave ; the externa], a, answers to the cuboid ; the inter- 

 nal, b, to the scaphoid. The tibial pulley, c, is strongly defined ; on the 

 posterior surface there is a large facette for the articulation with the 

 calcaneum, and two others in the external surface. This surface shews, 

 moreover, another for the articulation with the malleolar extremity of 

 the fibula, c (fig. 18), and there is one almost similar on the internal 

 surface, for the internal tibial malleolus. 



The calcaneum (plate 31, fig. 20, B), has the same surfaces and 

 facettes as that of the pig; but its body is thicker, shorter, and less 

 compressed. Its great astragalian surface is like-fl'ise broader. These 

 characters also serve to distinguish it from that of the ox. 



The cuboid (i5. C), corresponds in shape with the two preceding; the 

 surface towards the calcaneum is a little narrower than that towards 

 the astragalus, and its anterior surface, c, is somewhat in the form of a 

 carpenter's square. The inferior presents two facettes for the two external 

 bones of the metatarsus. Of these the external is very narrow, and above 

 it on the external surface of the bone there is another. The scaphoid {ih. 

 D) is separated from the cuboid as it is in the camel and the pig ; the 

 posterior tuberosity does not rise as in the latter. Its inferior surface 

 presents three facettes, two of which are for the two cuneiforme bones, 

 E and F, which answer to the two external bones of the metatarsus, 

 and the third is for a small supernumerary bone, partaking at once of 

 the first cuneiforme and of the toe. The cuneiforme of the internal side 

 is three times smaller than the other. What has been said of the toes 

 of the fore feet is also applicable to those of the hind feet. The bones 

 of the metatarsus and the phalanges bear the same resemblances and 

 the same difi'erences to the analogous boues of the pig. 



From this description it results, as may have been seen, that the 

 hippopotamus approximates to the pig and the ox in the structure of 

 its skeleton, while, at the same time, each bone furnishes such distinct 

 characters as must at once prevent its being confounded with that of 

 any other animal. 



All that now remains for me is, to give the dimensions of the differ- 

 ent parts of my skeleton, in order to convey a more correct idea of its 

 proportions. 



