. 1896.] -^-"-^ [Cope. 



There is considerable resemblance between several parts of this animal 

 and those of the stegocephalian Batrachia. This is seen in the forms of 

 the femur and of the shoulder-girdle, which are similar to those which I 

 have referred to Eryops. The close approximation of the huge auricular 

 meatus to the orbit is only seen elsewhere in the anurous Batrachia. 

 The teeth on the other hand are of strictly reptilian type in their mode 

 of implantation, and the lack of dentinal inflections distinguishes them 

 from those of many of the genera of Stegocephalia. There is nothing 

 in the shoulder-girdle to distinguish it from the Cotylosauria, and the 

 humerus so far as preserved is of the type of that order. It is impossible 

 to get at the occipital condyles without destroying important parts of 

 the specimen. The vertebrae are amphicoelous. 



It is probable that in life the species of this genus had an enormous 

 tj'mpanic drum. 



The tabular part of the skull is large as compared with the facial part. 

 Its posterior border is broken in the 0. testudineus, but it is continued to 

 a transverse line posterior to the auditory meatus. It was not probably 

 produced into horn-like processes. The suspensorial part of the quad- 

 rate is directed posteriorly below. The mandibular ramus has a hori- 

 zontal expansion of the inner side just anterior to the short angle. 



The clavicles have the distal expansion overlapping the episternum 

 characteristic of the order. The shaft makes an obtuse angle with the 

 expanded portion, and is compressed. Its proximal extremity is ex- 

 panded into a rounded disc, whose plane is horizontal and at right angles 

 to that of the shaft. Between the shaft and the mandibular angle the 

 edge of the pterygoid is visible. The episternum has the posterior part 

 broken off. The part preserved is a transverse plate, which has, like the 

 clavicles, a smooth surface. The scapula lacks the proximal end. Dis- 

 tally it presents a strong longitudinal ridge which extends to the cora- 

 coid. Anteriorly the shaft expands into a procoracoid laminar exten- 

 sion in its plane. The coracoid is small and has a convex internal bor- 

 der, which is not notched as in the Pelycosauria. It may be coossified 

 with the scapula. The humerus has a greatly expanded head and a 

 narrow shaft. 



The femur is longer than the tibia, and displays the condyles charac- 

 teristic of the Cotylosauria and Pelycosauria. They are unequally pro- 

 duced posteriorly. There is a long and strong anterior crest. 



Two vertebral centra are only moderately well preserved. They are 

 probably anterior dorsals. They are wider than long and are separated 

 by a large and protuberant intercentrum. A free intercentrum of the 

 same shape lies at one side. It is probable that a rather short neural 

 spine rises to the inferior side of the carapace. Only tire part next the 

 carapace can be seen in the specimen. 



The ribs are much expanded, but do not touch each other. The cara- 

 pacial bands alternate with them above, resting on their adjacent 

 edges and separated by narrow interspaces. Towards the supposed 



