32 ROY L. MOODIE 



was unable to locate it on the skull of Diplocaulus limbatus (Jope 

 which he figured in 1909. 



The nostrils are located far forward on the anterior edge of the 

 skull which curves slightly downwards so that they look forward. 

 The orbits are small, almost circular, and are situated far forward 

 as is the case in many of the carboniferous Microsauria. Other 

 than these there are no openings on the dorsum of the skull. 



The arrangement of the cranial elements is found to be approxi- 

 mately as Cope gave them in 1895 although there were discovered 

 in the complete specimen evidences of the postorbital which had 

 not been previously detected. Wilhston was unable to locate this 

 element in the excellent skull of Diplocaulus limbatus Cope and 

 concluded that the element behind the orbit is thepostorbitofrontal 

 (Trans. Kans. Acad. Science, 1908, pi. la) an interpretation which 

 is open to much question. We have yet to have a definite proof 

 of the union of these two elements, the postorbital and postfrontal, 

 in any vertebrate skull. If there be only one present it is either 

 one element or the other and not both. Further discussion of 

 this will be postponed for a paper on the development of the alli- 

 gator skull. The outlines of the jugal and quadratojugal were 

 also determined. The suture separating the parietal and the 

 supraoccipital was not found to be so erratic as Cope figured it 

 but it continues directly across the skull. This may easily have 

 been an individual variation. The suture separating the frontal 

 into two equal parts was not detected although careful search was 

 made for it. This seems to be the only case on record among the 

 Stegocephala in which there has been an actual fusion of two 

 paired elements of the cranium. Maggi has made some interest- 

 ing suggestions as to the origin of the interparietal of mammals 

 and its correlation with the fused epiotics of the Stegocephala. 

 In discussing Maggi's paper it was stated that there was no case of 

 a fusion of any of the cranial elements of the Stegocephala known. 

 This I believe to be an error as is demonstrated in the present 

 skull. This would not, however, change the decision in regard to 

 Maggi's conclusions. 



On the dorsum of the skull there were detected in several places 

 evidences of the lateral line canals which occur as shallow grooves. 



