ON THE BONKS OK THE RHINOCEROS. 425 



concave, and almost round. On the inner side it presents two facettes, 

 both semi-elliptical, for the os semilunare. 



The Pisiform bone, d, is oblong, thicker externally, and a little 

 crooked. Its cuneiform and cubital surfaces form together an angle 

 of sixty degrees, and are almost equal. 



The Trapezoid, g, has its upper and lower facettes concave. The 

 upper is curved externally, so as to present one of them to a conical 

 osselet, which rests also on the schaphoid and occupies the place of the 

 trapezium and of all the thumb. 



The Os Magnum, f, has its anterior surface rhomboidal, but the 

 lower edge is in the form of a convex semicircle. The upper is con- 

 cave, to give lodgement to the internal lower facette of the scaphoid. 

 The internal is sloped, by reason of the two facettes of the inner sur- 

 face, the upper of which is for the trapezoid, the lower for the external 

 facette of the head of the first metacarpal bone. The external edge is 

 rectilineal, and commences a square facette which corresponds first to 

 the unciform bone, and is then confounded with the schaphoidian fa- 

 cette, so as to form posteriorly a convex facette, which is lodged in 

 the external inferior concavity of the semilunar bone. Posteriorly 

 the os magnum has a thin and very prominent tuberosity. 



The Unciform bone, e, has its inferior edge semicircular ; the 

 superior is angular, by reason of the two facettes, both convex, which 

 it gives to the semilunar and cuneiform bones. The semicircular edge 

 is that of a facette, which proceeding from within outwards, is directed 

 over the outer side of the os magnum, over the external facette of the 

 head of the metacarpal bone of the digitus medius, over the principal 

 surface of the metacarpal bone of the digitus annularis, and over the 

 os rotundum, h, which replaces all the digitus minimus. This bone, 

 which also rests on the external surface of the head of the metacarpal 

 bone of the digitus annularis, is partly enchased by the projecting and 

 curved posterior tuberosity of the cuneiform bone. 



The metacarpal bones are depressed from before backwards ; the 

 external ones are curved a little outwards towards the lower part. 

 The pulley of their lower head presents its middle ridge only poste- 

 riorly. 



None of these bones can be confounded with those of animals of the 

 same size. The tapir, as we have said, presents the closest resem- 

 blance, but its small size prevents its being confounded. 



6. The Posterior Extremity. 



The Pelvis (plate 43, fig. 6) is extremely broad, and the elephant is 

 the only quadruped that resembles the rhinoceros in that respect : but 

 that of the rhinoceros is distinguished at once by its forked spine, a. 

 The angle of the os ilium, which touches the sacrum, is besides more 

 raised, and the neck, g, is much longer and narrower. 



The external edge of this bone, a b c, is nearly as large as the internal, 

 d ef, whilst in the elephant it is much smaller. The crest of the pubis 

 commences from the upper part of the neck of the os ilium, in g. 

 The foramina ovalia are more broad than long. The tuberosity of 

 the ischium, h, is very large above, and in the form of a crotchet. 



The Femur of the rhinoceros (plate 41, figs. 1,2, 3, and 4), is perhaps 



