IO8 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



it is seen to be made up of pits and elevations much as we find in the skull of 

 Saitrer peton lati thorax Cope. The left squamosal also shows sculpturing, which here 

 tends to take the form of grooves and ridges, and also of pits and elevations. It is 

 quite probable that the anterior portion of the skull was ornamented with grooves 

 and ridges and undoubtedly the lateral-line canals were well developed. The post- 

 frontals and the postorbitals are both large and elongated. The postorbital is 

 especially large. The supratemporal apparently separates the tabulare and the 

 squamosal in their posterior extremities. The squamosal projects posteriorly to the 

 tabulare and apparently even goes beyond the limits of the exoccipital. The out- 

 lines of the jugal are fairly definite, as are also the limits of the maxilla. 



MEASUREMENTS OF THE TYPE OF THE SKULL OF ERPETOSAURUS ACUTIROSTRIS MOODIE. 



mm. mm. 



Length of skull 50 Width across orbits. . . . 3 1 



Interorbital space 9 Posterior width of skull ... .50 



Width of orbit. . 7 Diameter of pineal foramen I 



Length of orbit .... . . . 10 Length from tip of snout to posterior angle of skull. . 65 



An additional specimen shows that the skull, of which the anterior half is pre- 

 served, is practically of the same size as the type and shows much the same characters, 

 though more extensively. The sculpture of the squamosal region is not confined to 

 that portion of the skull, but extends throughout the cranial elements, apparently 

 including the premaxillas. 



The sutures, which are clearly distinct, are of the same type as has been described 

 for the type specimen. Perhaps one of the most interesting characters discovered 

 on the present specimen is that of the greater part of the left supraorbital lateral- 

 line canal, which is exhibited as a rather deep and broad canal running in a slight 

 curve across the lower edges of the postorbital and the parietals and partly 

 cutting the jugal. 



On the left of the fossil, as it is preserved, there is an indistinct impression of the 

 clavicle, with the sculpture in radiating lines from the apex as a center, such as have 

 been found in other species of the Tuditanidae. 



MEASUREMENTS OF ADDITIONAL SPECIMEN. 

 (No. 8607, American Museum of Natural History.) 



mm. mm - 



Length of skull as preserved . . .40 Length of clavicle . . .18 



Anterior width across orbital region 22 Greatest width of clavicle . . 9 



Greatest width of the skull . . .33 



Still a third specimen of this species is possibly represented by a nearly complete 

 skull of a small individual which exposes the mandible and the ventral portion of the 

 skull. The remains are crushed flat, though not at all distorted. It is quite pos- 

 sible that the present specimen represents a distinct species, but only a small portion 

 of the dorsum is present and the shape of the cranium is indistinct, so it is retained 

 in this species. The portion of the skull shows the sculpture to be quite similar to 

 that of Erpetosanrus acntirostris, so far as the species is known; and the skull appar- 

 ently tapers to a point anteriorly. It may be a dwarfed or immature form. The 

 sculpturing of the jaw is such as we would expect of this species. 



