ON THE BONES OF THE HIPPOPOTAMUS. 383 



The humerus (plate 30, fig. 1 B, and plate 31, figs. 7, 8, 9, 10), has 

 its large tuberosity, a, very much elevated, very salient in front, and 

 dividing' itself into two lobes, the posterior of which, d, is the smaller; 

 the anterior curves forward from the bicepital groove, which is very deep 

 and smooth ; the smaller, b, is lower down. The articulated head, c, is 

 directed very much towards the back, and is oval ; the sharp line 

 stretches obliquely along the whole of the bone ; at first it is not at all 

 salient, but it swells, immediately below the upper third of the bone, 

 into a tuberosity, (c^ <?,figs. 7 and 8) ; the external condyle, gf, is more salient 

 than that of the internal, /: but its crest does not project beyond it 

 along the bone as it does in the elephant : the articular pulley, h, is ob- 

 lique from the out to the inside, thicker on the internal side, with a 

 wide gorge very slightly concave, and a strait still less concave on the 

 outside. To the rear between the two condyles (i, fig. 8), is a fossa for 

 the olecranon, very deep, but not piercing the bone. Neither is there 

 in the internal condyle any hole for the cubital artery. This humerus 

 bears a singular resemblance to that of the ox, which is merely shorter 

 in proportion, and has the grooves of its pulley more marked ; that of 

 the pig has also some relation to it, but is not so large at the base. 



The radius, E, (fig. 1, plate 30), and a b, (fig. 11, plate 31), is thick 

 and short, somewhat flattened from front to rear. Its upper head, c d, 

 (fig. 12, b), is transversely oblong, larger on the inside, and rather salient 

 in the centre, e, which only allows it a flexional movement on the humerus. 

 It very soon adheres by its posterior margin to the inferior margin 

 of the sigmoid facette of the cubitus. Its anterior surface represents, 

 though irregularly, a portion of a cylinder : the internal surface is level. 

 It adheres by the whole exterior margin of this surface, to the anterior 

 margin of the cubitus. 



Its lower extremity (e /, fig. 11), presents two oblique concave 

 facettes below, g and h, for the tv/o first bones of the carpus, and two 

 thick tuberosities in front. The external margin of the second facette 

 becomes united to the anterior or internal margin of the cubital facette. 

 The cubitus, F, (plate 30, fig. 1), and c d, (plate 31, fig. 11), is com- 

 pressed ; the olecranon, c, is rather prolonged, and its posterior margin 

 almost sharp : to the rear it is somewhat rounded, and is rather sharp 

 above. At the extremity, this sharp margin bends inward in the form 

 of a crotchet. The sigmoidal facette is narrow above ; towards the 

 base it enlarges, and becomes two-pronged, as in most other animals ; 

 but this latter quality is separated entirely from the other by a deep 

 fossa, and forms a distinct facette. 



The lower facette of the cubitus is small, concave, and becomes uni- 

 ted to a slight portion of the radius, to form a third oblique pulley for 

 the corresponding bone of the carpus. 



The two bones just mentioned form in reality but a single one in 

 the hippopotamus, for they become identified with each other very soon, 

 merely leaving between them on the external side a rather deep furrow, 

 which occupies three quarters of the length of the radius, and on the 

 internal side a simple ajjerture towards the upper quarter. 



The fore-arm of the ox is very similar to that of the hippopotamus ; 

 but it is more elongated, and the articulations of the lower extremity 

 are less oblique. 



