114 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



inclosed in the median suture in the anterior third of the parietals. The parietal 

 has the usual relations of that element. The postparietal lies posterior to the parie- 

 tal, but a portion of its bounding sutures are destroyed. The prefrontal forms the 

 antero-interior border of the orbit and borders the postfrontal posteriorly, in an 

 unusual manner. The lacrimal is a large element and is clearly separable from 

 the other cranial elements. It, with the prefrontal, forms the anterior border of 

 the orbit. The maxilla is very elongate and forms the larger part of the lateral 

 border of the skull. Sharp -pointed teeth are present on it and they may have been 

 pleurodont. The lateral border of the orbit probably received a portion of the 

 maxilla. The postfrontal and the postorbital form the greater part of the poste- 

 rior boundary of the orbit. The postorbital seems to be divided by a median suture 

 which would indicate an intertemporal bone, but this is not certain. The appear- 

 ance may be due to a fracture. The supratemporal is a large element bordering 

 the parietal and lies in front of the tabulare. The squamosal is elongate to form 

 the posterior horn-like extension of the skull. The tabulare is transversely elon- 

 gate and has the usual relations. The jugal widens to a fan-shape backwards, and 

 helps to form the lateral border of the orbit. Its lateral and anterior boundaries 

 are not assured. The quadrato jugal seems to lie as indicated, although the ante- 

 rior part of the suture is not distinct. It is apparently an elongate element and with 

 the maxilla forms the lateral border of the skull. The base of the skull as restored 

 (fig. 23) is irregular and may have had a slightly different form. 



The genus Stegops is exceptional in the elongate character of the cranial ele- 

 ments of the single species known. In this respect it recalls the species Dicerato- 

 saurus IcEvis described below. The large size of the nasals, frontals, and lacrimals 

 and the small size of the parietals are, so far as I am aware, unparalleled among the 

 other Coal Measiu^es Amphibia of North America. 



Measurements of the Type. 



mm. mm. 



Median length of the skull 56 Intcrorbital space .' 16 



Width across tips of horns 46 Length of the nostril 2 



Width at base of horns 40 Diameter of the pineal foramen i 



Width across orbits 44 Length of the teeth 1.5 



Diameter of the orbit 8 Length of the horn from base 7.5 



Length of the orbit 15 Width of horn at base 4 



