THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. X, No. 10.] January, 1917. [.^."'x'l'^^^fo. 



Eryops; Eryopsoides, Gen. Nov. from the New Mexico 



Permian. 



BY HERMAN DOUTHITT. 

 SKULL STRUCTURE. 



THE statements made herein are based upon the study of eight 

 skulls in the University of Chicago collection, some incom- 

 plete, and some only partly uncovered at the present time; one 

 incomplete skull loaned from the Yale Museum for the purpose 

 (No. 826); one skull and fragmentary material from the Univer- 

 sity of Kansas collection; and descriptions by Branson, Case and 

 Broom. Shortly after this work was undertaken, in the fall of 

 1913, a paper by Broom appeared which covered to a large extent 

 the same field. The moi-phological part, therefore, is presented 

 mainly as a review and criticism of the work of Broom. 



The structure of the upper surface of the skull was found to 

 offer no disagi-eements from the results made known by the in- 

 vestigations of Branson, Case and Broom, and need not be dis- 

 cussed here. A few slight disagreements were found, which rep- 

 resented probably mere indi\ndual differences. 



The occipital region and base of the skull were found to agi'ee 

 with the accounts of Broom, except that there is considerable 

 evidence that the supraoccipital is present. Xo separation could 

 be made out of the elements designated by Broom as basisphenoid 

 and sphenethmoid, but there appears no reason for doubting his 

 determination. As regards the supraoccipital, exidence of its 

 presence is provided by one small, apparently immatui"e, skull. 

 The sutures extend from just dorsad of the condyles, dorsad and 

 laterad, the supraoccipital thus forming more than one-half of the 

 border of the foramen magnum. None of the larger skulls at hand 

 give satisfactory evidence of its presence, though several are well 

 preserved. 



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