ON THE OSTEOLOGY OF RISSo's GRAMPUS. 
417 
HYOID BONE. 
Composed of two boomerang-shaped masses, superimposed and 
connected in the centre by cartilage. Superior arch, composed of 
two bones ; inferior, composed of three — a quadrilateral body and 
two wings. 
SCAPULA. 
in. lines. 
Triangular . . . greatest width 7 0 
„ „ depth 9 2 
Acromion and coracoid processes well developed. 
HUMERUS. 
Massive (cylindrical) . . . ..40 
ULNA. 
Length ' . . . . ..39 
RADIUS. 
Length . . . . ..46 
Carpal bones tessalated in cartilage, with semi-lunar articulating 
discs between these and the bones of the forearm. The manus 
possess bones in only two digits ; the third had seven phalanges, 
and the fourth six phalanges, with intermediate discs. The bones 
of the forearm were very similar to those of a porpoise, except 
the phalanges. 
