Australia.

Family 2. TRICHECHIDÆ.

Trichechidæ, Gray, Ann. Philosoph. 1825, p. 348; Ann. & Mag. N. H. 1869, iv. p. 268.

Rosmaridæ, Gill, Proc. Essex Inst. v. 1866, p. 11.

Trichechina (part.), Gray, Cat. S. & W. p. 33.

Muzzle very broad, truncate, convex, swollen above. Ears without any conch. Eyes prominent. Canines very large, exserted. Cutting-teeth 4/2 in young, and 2/2 in adult; grinders all single-rooted. The anterior feet as large as the posterior ones; the fingers decrease in a curved line, destitute of claws; the hind feet with five toes, very gradually increasing towards the inner, all provided with claws; palms and soles hairy in the young, becoming chaffy. Tail rudimentary. Skull with no postorbital processes. A distinct alisphenoid canal. Mastoid process strong and salient, with its surface continuous with the auditory bulla. The scapula, hinder margin nearly straight, with the spine a short distance from and somewhat parallel with it. Resting on its body with the fore feet extended and the hind feet doubled under it, moving by the exertion of the abdominal muscles. (See P. Z. S. 1853, p. 112.)

1. TRICHECHUS.

Trichechus, Gray, Cat. S. & W. p. 35.