92 



AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



skull and look outward and upward. There is no trace of lyra or mucous 

 grooves. 



The rugose condition of the skull makes it difficult to trace the sutures 

 of the upper surface, but Branson (2) has worked out most of them in speci- 

 men No. 117 University of Chicago, fig. 24. These correspond, in a general 

 way only, with those of a small specimen, No. 4310 Am. Mus., regarded as 

 a young Eryops (fig. 26). 



The premaxillaries are large and form the extremity of the nose. The 

 character of the sculpture is shown in plate 8. 



The nasals extend far forward in the middle line, and then recurve to 

 take part in the edge of the nares; several specimens show the same notch 

 in the suture line just inside the nostril. Posteriorly they seem to contract 

 and to include the sharp anterior end of the frontals. 



Fig. 24. — E. megacephalus. No. 117 Univ. 



of Chicago. X it circa. 

 Upper view of skull, showing sutures slightly 

 modified from Branson. Lettering as usual. 



Fio. 25. — E. megacephalus. No. 4673 Am. Mus. 



A, Lateral view of anterior part of nose. Lettering 



as usual. 



B. The same, anterior part of nose, showing sutures. 



The septomaxillary: Within the nares of specimen No. 4673 Am. Mus. 

 are small elements bent at right angles, so that they form the back and 

 bottom of the nares. These are the turbinated bones of Cope or the septo- 

 maxillaries of Swinnerton and Howse. 



The lachrymals are narrow bones, taking part in the posterior edge of 

 the nostrils, but not, according to Branson, reaching back to the orbits. 



The maxillaries are more elongate than is indicated in Branson's figure; 

 on the lower face they reach back to a point posterior to the orbit. 



The prefrontals are nearly square and form the inner anterior edge of 

 the orbit. They meet the postfrontals and exclude the frontal from any 

 part in the orbit. 



The frontals are relatively small, the two bones coming to a point ante- 

 riorly and inclosed by the nasals. The posterior ends include the anterior 

 ends of the parietals. 



