Paronychodon lacustris, Cope, 1876

Cope, E. D., 1876, Descriptions of some vertebrate remains from the Fort Union beds of Montana, Proceedings of the Academy of Natural Sciences of Philadelphia 28, pp. 248-261 : 256-257

Paronychodon lacustris , gen. et sp. nov.

Char. Gen. - The teeth which characterize this genus have the general character of those of Plesiosaurus , Elasmosaurus , etc. The crowns are subconic, and the enamel is thrown into longitudinial plicae. The special characters of the genus are seen in the form of the crown, one side of which is convex, and the other side plane, so that the section instead of being circular is seimicircular. It is also strongly curved in the direction of its plane face.

Char. Specif. - Both anterior and posterior edges are curved, and are not acute nor denticulate. There are four plicae on the flat face, only two of which approach the apex. There are six keels on the convex face, all of which approach the apex. All the carinae are rather obtuse, and the enamel is otherwise smooth. The apex is very acute.

Measurements.	M.
Length of tooth	.0130
Diameter at base antero-posterior.0040 transverse.0024	.0040 transverse.0024
Length of crown	.0100

It is probable that portions of skeleton of this reptile are in my possession, but the means of positive identification are yet waniting.