The vertebrata of the Trias of North America are not as yet well known, and scarcely twenty species have been described. Those known to the writer in 1870 are enumerated in the Transactions of this Society, Vol.XIV; and the species discovered in Pennsylvania are catalogued in the Proceedings of this Society for 1886, p.403. Some species from New Mexico are described in the American Naturalist, 1881, p.922, and April, 1887. Descriptions of several forms from this formation, from the Rocky Mountain region, with plates, were given in the Report of the U.S. Geol. Geogr. Survey W. of the 100th Meridian, 1877.
I am now able to add descriptions of some new species from New Mexico; and furnish additional characters of species already described.