12 GfiOLOGtCAL StRVEY OS' *EXAS. 



Fragments, probably representing the Batrachian genus Eupelor of the 

 Atlantic Trias, also occur. 



There can be no difficulty in distinguishing the Triassic from the Per- 

 mian formations, if remains of the reptilian fauna are present; the change 

 of type was radical, and there are no resemblances between the forms of 

 the respective horizons. 



The lacustrine conditions which I ascertained to have prevailed in New 

 Mexico also characterize the formation in Texas. I obtained in the 

 former region the Unio tefrroerubroe of Meek; while Mr. Cummins dis- 

 covered extensive beds of Unios in the Trias of Northwest Texas, com- 

 posed of a species to which he has given the name of Unio dockumensis. 



The vertebrate fossils are always fragmentary, so that but few of them 

 can be satisfactorily determined. 



BATRACHIA. 



As already remarked, fragments of a species of this class are found in 

 the Dockum beds. They have been found most abundantly near to 

 Dockum. They consist of fragments of dermal and cranial bones, which 

 exhibit the regular honey-comb pitting of the Pennsylvania species of 

 Eupelor. A phalange found also resembles that of the Permian genus 

 Eryops. 



REPTILIA. 

 BELODON, Meyer. 



Fragments of the skeleton of species of this genus are the most abun- 

 dant fossils found in the Dockum beds. They are, however, generally 

 scattered and fragmentary. An exception of this condition occurred 

 near Dockum, where a considerable part of the skeleton of one individual 

 was found together. 



BELODON SUPERCILIOSUS, CopC. 



Sp. nov. Plate I. 



This saurian is represented by a number of fragments of the skull, in- 

 cluding the left frontal bone, with the greater part of the postfrontal and 

 parietal attached in place; fragments of the splenials, quadrates, arches, 

 etc., with a very few fragments of vei-tebrae — one including the right 

 half of a centrum; parts of femur, fibula, and other long bones, with 

 numerous dermal bones and several teeth. These were all found together 

 in a light gray bed not far from the red bed which contained the remains 

 of the typical specimen of Episcoposaurus haplocerus.* 



The dermal bones have the characters of those of the European Belo- 



*Proceed, Amer. Philosoph. Soc, 1892, p. 129, 



