1870.]} ANATOMY OF THE PRONGBUCK. 365 
grooved and ridged posteriorly for the attachment of the long flexor 
muscles. The internal malleolus is large, triangular, and flat. 
The tarsus consists of os calcis, astragalus, adnate cuneiforms, 
scaphoids, and a cuboid. 
Fig. 8. 

The male pelvis: a. s. sp. Anterior superior spinous process; ¢. sp. External 
ischial spine or tuberosity ; ¢. 2. Tuber ischium. 
The conjoined metatarsals of the hind limb or cylindrical cannon- 
bone, as in the majority of Antelopes and Deer, evinces a greater 
tendency to duplicity than does its equivalent bone of the pectoral 
extremity—this by its being grooved throughout in front, but not 
deeply cleft. There is also longitudinal grooving in its after surface, 
but only in its lower part, the gutter being shallow. This cannon- 
bone measures 8-7 inches in long diameter, and shows a very slight 
lateral flattening of the shaft. There is an entire absence of acces- 
sory splints, or rod-spicules, corresponding to extra metatarsals, and 
the same may be said of the metatarsal segment of the fore limb. 
The osseous conformation thus tallies with the outer aspect of the 
legs in deprivation of false hoofs. 
The digits and their additional sesamoidea are completely identical 
with those of the fore foot. 
C. Vertebral Column and Thorac. 
(a) Spine.—The vertebral elements present in the spinal column 
Proc. Zoou. Soc.—1870, No. XXV. 
