April 15, 1887.] -^^^ [Cope. 



PROCEEDINGS 



OP THK 



AMERICAN PHILOSOPHICAL SOCIETY, 



HELD AT PHILADELPHIA. FOR PROMOTING USEFUL OOWLEDGE. 



Vol. XXIV. July to December, 1887. No. 126. 



A Contribution to the History of the Vertehrata of the Trias of North 

 America. By E. D. Cope. 



[Read before the Americnn Philosophical Society, April 15, 1S87.) 



The vertebrata of the Trias of North America are not as yet well known, 

 and scarcely twenty species have been describecl. 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. 

 Oeol. Geogr. Survey W. of the 100th Meridian, 1877. 



I am now able to add descriptions of some new species from New Mex- 

 ico ; and furnish additional characters of species already described. 



1. EuPELOR DURUS Cope. Transac. Amer. Philos. Soc, 1869, p. 25, 

 V. xiv. 

 A good many fragments of this species or one nearly allied to it were 

 obtained by Mr. C. M. Wheatley, in York county, Pennsylvania. These 

 pieces are not all as yet identifiable, but one of them consists of a large 

 part of the ramus of the lower jaw which supports the bases of the pos- 

 terior teeth, but from which the cotyles and angles have been broken off. 

 The bases of the teeth are cylindric, and show delicate grooves, being 

 similar to those of Eryops, and proving that my original reference of 

 teeth to this genus was probably correct. All the bones show the coarse 

 honeycomb pattern of sculpture of the external surfaces characteristic of 

 the species. Towards the margins of the bones the pits become confluent 

 into radiating grooves. A subtriangular plate measures : 



M. 

 Length 345 



Greatest width 140 



* Belodon biiceros and B. scolopaz Cor>e. 



PROC. AMER. PHILOS. SOC. XXIV. 120. 2 A. PRINTED JULY 8, 1887. 



