5. Crocodilus humilis, Leidy.

The species is founded on ten specimens of shed crowns of teeth, apparently of a small species of crocodile. The largest specimen is 7 1/2 lines long and 3 1/2 lines in diameter at base, which is nearly circular. Another specimen is 7 lines long and 2 1/2 lines in diameter at base; and a third specimen is 6 lines long and 3 1/2 lines in diameter at base. These are all moderately curved conical, nearly circular in transverse section, with the two usual internal acute ridges, and with the intervening surfaces slightly striate or nearly smooth. The crown of a posterior tooth is compressed, mammillary in form, 2 1/2 lines long and 2 1/2 wide at base, with the summit obtuse, and the sides finely and longitudinally rugose.