Note 38 — Genus—ABROCOMA.[37]

There is a wide difference between the present animals and the Arvicolidæ in the form of the occipital condyles: the same difference is also observable between Echimys and Mus. The Octodontidæ in fact have the same form of condyles as the Chinchillas and Cavies. In this and many other characters the last mentioned animals evince an affinity to the Leporidæ.