58 



AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



"In the presence of the meatus auditorius this family differs from the 

 Other members of the Cotylosauria. In the latter the vestibular space is 

 inclosed by the lateral part of the temporal roof, and has no distal inferior 

 bounding wall. The meatus results in the Otocoelidae, not merely from the 

 excavation of this roof but also from the excavation of the posterior border 

 of the suspensorium. In Conodectes the excavation is not great but in Otocce- 

 lous it is very considerable, the proximal extremity of the suspensorium having 

 the anterior position seen in the Loricata and the Testudinata. It resembles 

 the quadrate of the latter in the decurvature of the proximal extremity 

 into a descending hook, which partially bounds the meatus posteriorly. 



"This meatal excavation constitutes an approximation in the Cotylo- 

 sauria to other and later orders of the Reptilia, where it is nearly universal. 



It is interesting to observe 

 that it precedes in time the 

 division of the roof into lon- 

 gitudinal bars by perfora- 

 tion, in the series of which 

 the Otocoelidse form a part. 

 This fact renders it probable 

 that it is from this family 

 that the Testudinata has 

 descended. The arrange- 

 ment of the clavicles and 

 episternum is quite like that 

 of the corresponding ele- 

 ments in the anterior lobe 

 of the plastron of the tor- 

 toises. The median and 

 posterior part of the abdom- 

 inal wall of the Otocoelidse is not known. The teeth are quite insignificant, 

 and their loss would bring us again to the Testudinate type. Their implan- 

 tation in deep alveoli is reptilian in character. * * * 



"In this family the slight, posterior concavity of the quadrate region 

 of the Diadectidse is extended forwards to a great distance, and the osseous 

 tympanum is produced further outwards. The position of the parts is dif- 

 ferent from that which is characteristic of the Stegocephalia, where the 

 tympanic notch, when present, is superior, owing to the much greater length 

 of the suspensorium. The dental characters also distinguish the family from 

 the Diadeciid^. No ossicula auditus were found in the tympanic cavity." 



Genus OTOCCELUS Cope. 

 Am. Nat., vol. xxx, 1896, p. 399; Proc. Am. Phil. Soc, vol. xxxv, 1896, p. 125. 

 Type: Posterior portion of a skull with the pectoral girdle and a part 

 of the carapace. No. 4343 Am. Mus. Nat. Hist. Cope Coll. From Texas. 

 Original description: Distinguished from the nearly related Conodectes 

 by Cope as follows: 



"Suspensorium directed anteriorly, except at free extremity; nostrils lateral. Otoccelous 

 Suspensorium directed posteriorly; nostrils vertical Conodectes" 



The same article gives a further description of the genus: 

 "Intercentra present. Teeth subconical. Mandible not projecting 

 beyond the quadrate. Clavicle expanded at both extremities, overlapping 



A vj — ^ "^ — a B 



Y\c. II. ^C. favo'us. No. 4342 Am. Mus. X K- 



A, upper view of skull; B, lower view. Shaded portions restored 

 in plaster, pt, pterygoid. 



