MORPHOLOGICAL REVISION 113 



Family PANTYLIDAE. 

 Genus PANTYLUS Cope. 

 Pantylus cordatus Cope. 



Characteristic specimen: The type, No. 4330 and No. 4331 Am. Mus. Nat. Hist. 

 Cope Coll. 



The type specimen consists of a skull with the upper portion well preserved, 

 lacking only the bones of the temporal region, but with the course of the sutures 

 preserved on the cast of the lower surface. The lower jaw of the right side is in 

 place. The left jaw is broken away at the middle of the maxillary. The bones of 

 the back of the skull and the palate are largely destroyed. 



Originally referred by Cope to the Stegocephalia (24), Pantylus was recog- 

 nized by him as a reptile in 1882 (26). In 1892 (35) he compared Pantylus with 

 Chilonyx, noting that it differed in the fact that the suspensorium was directed 

 straight downward instead of forward. In the series of figures there published 

 for the first time and several times repeated (36, 42, 44) Cope figured this animal 

 correctly as having the full complement of bones in the temporal region, i. e., 



Fig. 51. — Skull of Pantylus cordatus. X J. No. 4330 Am. Mus. 

 a, lower view; b, upper view. 



squamosal, prosquamosal, jugal, and quadratojugal. The posterior portion of the 

 prosquamosal is bent nearly at right angles and forms a portion of the vertical 

 posterior surface of the skull. There is no trace of the tabulare; it was either absent 

 or was reduced to small size, as in Captorhinus, and has been destroyed with the 

 median portion of the supraoccipital in the injury to the back of the skull. The 

 quadrate was originally completely covered, but the breaking away of the bones of 

 the temporal region shows that its upper part was a thin plate reaching to the top of 

 the skull and in contact with the quadratojugal, prosquamosal, and squamosal. 

 The inner face was overlapped by the vertical posterior end of the pterygoid. On 

 the lower surface can be seen the sphenoid processes of the pterygoids. Anterior 

 to these the inner edges of pterygoids are concave, leaving a large interpterygoid 

 space. The edges of this portion of the pterygoid are lined with minute teeth. 

 This peculiar vertical termination of the posterior part of the skull extends to the 

 posterior end of the lower jaw. 



On the left side the posterior portion of the maxillary is broken away, showing a 

 closely set group of strong crushing teeth on the palate, and in specimen 4331 the 

 posterior portion of the lower jaw shows a corresponding and opposed set. In this 

 regard Pantylus resembles Naosaurus {Edaphosaurus); it is, however, but a devel- 

 opment of the condition found in Captorhinus. 



