TAUT 4.J 
lyde&ker: Osteology of Merycopotamus dmimiltx. 
153 
surface. Length 1-5 indies ; transverse diameter of proximal surface 0 7 inch ; antero¬ 
posterior diameter of proximal surface O'fi inch; transverse diameter of distal surface 0'55 
inch. 
Forearm. —Of the forearm, we only know at present the lminerns from its two extremi¬ 
ties, the radius, and the distal extremity of the ulna ; the two former bones are figured 
by Falconer. 
Humerus. —At the proximal extremity we distinguish the humerus from that of Hippo¬ 
potamus by the great tuberosity being less developed, which renders the bicipital groove less 
closed in by bone: the bicipital groove is unusually wide, and the deltoid ridge strongly 
marked; the posterior extension of the great tuberosity forms a more continuous rim round 
the outer border of the superior surface than in either J hippopotamius or Sun. The distal 
extremity agrees with Hijipopo/tnnns, and differs from Sms in the absence of the supra¬ 
trochlear foramen; the trochlear surface has the ridge on the radial half more prominent 
than in either of the allied genera ; the ulnar condyle is more prominent than in Hippopo¬ 
tamus. Width of proximal extremity S o inches ; width of distal extremity 2'3 inches. 
The shape of the distal extremity is like that of the humerus of Anthracotherium, but the 
supra-trochlear fossa is deeper, 
Radius and ulna.— The radius and ulna resemble those of the Pig, and differ from 
those of the Hippopotamus in being quite free throughout their entire length. The radius 
is a twisted bone with a triangular shaft; it is Hatter than in the Pig, and is broader at the 
proximal and narrower at the distal extremity, so that the latter is the widest of the two 
surfaces; whereas the reverse is the ease in the Pig : the bone is not contracted in the middle, 
ns in Hippopotamus. The distal extremity of the ulna, on the other hand, is larger than in 
the Pig, and the bone takes a larger share in carrying the carpus: the larger size of this 
extremity' of the ulna is a Hippopotamive character. The length of the radius is 7'3 inches, 
the width of the proximal extremity 1'7 inches, and of the distal extremity l'Oo inches. 
The greatest length of the distal articular surface of the ulna is T2 inches. 
Position of genus. —From the above comparisons it will be seen that the osteology 
of Merycopotamus, as fur as we know it, is very closely allied to that of Hippopotamus 
and Sue, bur it presents certain characters different from that of both genera. Beyond a 
slight resemblance in the form of the teeth and of the astragalus, it does not show affinity 
to the Annplotheres, among which it is placed by Pictet. I should be inclined to place the 
genus in the family Hippopotamida, forming a link between that and the Anlhracotheridce ; 
the three genera Merycopotamus, Hyopotamus and Anthracotherium are aberrant forms, 
connecting the Suine to the Anoplotheridce and the Eunvinantia. 
A curious mistake has been made regarding this genus by M.M. Pictet and de Blain- 
ville in the Traite de Paleeo-ntologie (vol. I, p. 322) of the former writer ; a lower jaw de¬ 
scribed by Falconer (Journal Asiatic Society,.(Bengal, vol. VII, p. 1038), under the name of 
Hippopotamus dissimilis is placed under the genus Hippopotamus, with the remark—“ Je 
pense que eette espece estla mimequecellequiest ligureedans le Fauna Antigua Sivalensis, 
sous le nom de Tetraprotodon Pahmndicus.” ! In reality, the jaw should have been placed 
under the genus Merycopotamus, which is also described in the same work (p. 342) ; before 
the latter genus was determined, Falconer had referred all the bones belonging to it to Hip¬ 
popotamus dissimilis. M. de BlainviUe has made a similar error to that of M. Pictet. 
