ANTILOCAPRIDA 333 
the limbs and cervical vertebrae were decidedly shorter, although of 
a similar slender type. Helladotherium, of the Pliocene of Greece 
and India, is represented by a species of considerably larger size 
than the Giraffe, with no appendages or lachrymal vacuity to the 
skull, and with shorter and stouter limbs and neck. 
Hydaspitherium, Bramatherium, and Sivatherium are Indian genera, 
characterised by the presence of large palmated and antler-like 
cranial appendages, varying considerably in arrangement. The 
former genus has a large lachrymal vacuity which is absent in the 
two latter. In the first and second genera all the appendages rise 
from a common base; but in Sivatherium there is a pair of simple 
horn-like projections on the orbits in addition to the posterior 
palmated antlers. Stvatheriwm was an animal of huge bulk, being 
the largest known representative of the Pecora. 
Another apparently allied type is Samotherium, of the Pliocene 
of the Isle of Samos, which appears also to have some affinity with 
the Antelopes. The skull is nearly as large as that of the Giraffe, 
and is of the same elongated shape, although depressed between the 
conical horn-cores, which rise vertically above the orbits, and without 
a median bony prominence on the frontals. The horn-cores form 
mere processes of the frontals. The diastema and the mandibular 
symphysis are shorter than in the Giraffe, and the latter is less 
deflected. The teeth, although larger, are almost indistinguishable 
from those of the Giraffe, the only well-marked difference being that 
the last lower premolar has a double in place of a single postero- 
internal column. 
Family ANTILOCAPRIDA. 
Closely allied to the Bovide, but the horns deciduous and branched. 
Antilocapra1—The Prongbuck, or Prong-horned Antelope 
(Antilocapra americana), as the single existing member of this family 
is called, is an animal of nearly the same size as the Fallow Deer, 
but of a lighter and more graceful build. It is an inhabitant of the 
prairies of North America, where it is one of the few representa- 
tives of the Cavicorn Pecora. The bony horn-cores are unbranched, 
and form vertical, blade-like projections immediately above the 
orbit. The horns themselves are compressed, and nearly one foot in 
length, having a gentle backward curvature, the short branch arising 
somewhat above the middle of its height, and inclining forwards. 
When the horn is about to be cast off it becomes loosened, and a 
new one is formed upon the bony core beneath it. The ears are 
long and pointed, and the tail is short. The neck has a thick mane 
of long chestnut-coloured hair, and there is a white patch on the 
rump. 
1 Ord. Journ. de Physique, vol. Ixxxvii. p. 149 (1818). 
