The group at the present day is divided into Girafjidae (giraffe and okapi), Cervidae (deer), Antilocapridae (prongbuck), and Bovidae (oxen, sheep, goats, antelopes, &c.).
The above-mentioned four types of skull appendages are generally regarded as severally characteristic of as many family groups, namely the Giraffidae, Cervidae, Antilocapridae and Bovidae.
As a temporary measure it seems preferable to regard Merycodus either as representing a distinct subfamily of Antilocapridae or a family by itself, the latter course being adopted by Mr Matthew.
The Antilocapridae (prongbuck), whose relationships appear to be rather with the Cervidae than with the Bovidae, are on the other hand apparently a North American group. The chevrotains (Tragulidae), now surviving only in West and Central Africa and tropical Asia, are conversely a purely Old World group.