Cope.] ^^ [August 15, 



Fifth Contrihxdion to the Knoxdedge of the Fauna of the Permian Formation 

 of Texas and the Indian Territory. By E. D. Cope* 



{Read before the American FhilosopMcal Society, Avgust 15, ISS4.) 



PISCES. 

 Ceratodus FAYOsrs, sp. nov. 



This species is known to me from a piece of the lower jaw, which sup- 

 ports a tooth. One extremity of the tooth is broken off, but from the cur- 

 vature of its inner side, it is to be inferred that the portion lost is but small, 

 probably including one of the three processes which the tooth possesses. 

 The species may be distinguished from those described by Agassiz, and 

 from the existing species, by the great depth of the two emarginations of 

 the external side. These enter the crown so deeply as reduce its width to 

 dimensions no greater than those of each of the processes of the crown. 

 The internal foce is strongly convex, and one extremity is more strongly 

 recurved than the other. The crown consists of a mass of coarse perpen- 

 dicular simple calciferous tubules, -which are enclosed in a rather thin 

 layer of a dense substance which thickens downwards, and laps over the 

 external fece of the jaw bone. The external surfoce of this layer is 

 vitreous. The walls of the tubules are of a dense and hard substance, of 

 a darker color in the fossil, and the tubules are filled with a softer sub- 

 stance, so that the grinding surface of the crown has the appearance of a 

 small honeycomb. The diameter of the tubules ranges from 1. to .05 mm. 

 The fragment of jaw is robust, is deeper than wide, and is strongly con- 

 vex on the internal face. The internal inferior angle rises atone extremity 

 above the level of the external inferior angle. The processes of the crown 

 project freely beyond the bone, having rested on the cartilage which forms 

 the external face of the jaw, as Giinther has shown to be the case in the 

 C. forsteri. 



Besides the deep emarginations of the crown, the coarseness of the cal- 

 ciferous tubules is a special character of this species. 



Measurements. M. 



Depth of jaw with tooth 019 



" " without tooth 013 



Width of crown at middle process 014 



Probable length of crown 022 



Found by Mr. W. F. Cummins. 



Agassiz did not record any species of this genus from below the Trias, 

 but Fritsch has reported them from the Permian of Bohemia. 



BATRACHIA. 



Cricotus crassidiscus, sp. nov. 



Accession of additional material enables me to add several points to the 



*The "Fourth Contribution" will be found at page 628 of these Proceedings 

 for the year 1833. 



