1882.] 449 [Cope. 



a deep anteroposterior concave emargination. There is a flat bone ex- 

 tending from it anteriorly wliich is apparently pterygoid rather than 

 quadratojugal. The tooth bearing portion terminates opposite the middle 

 of the basisphenoid. 



The occipital condyle is undivided, and thu biistsphenoid presents the 

 usual two divaricating protuberances to the basioccipital. 



Edaphosaurus pogonias, sp. nov. 



Represented by the followsng portions of a skull ; basis cranii vfith por- 

 tion posterior to the middle of the parietal bone ; left maxillary with dental 

 plate , left mandibular ramus entire ; various flat bones undetermined. 

 There is also a body which may be the atlas with its arch somewhat dislo- 

 cated. These pieces are in part covered with a thin layer of the red deposit 

 of the Permian bed in which they occur. 



The facial plate of the os maxillare is subvertical, so that the orbit is 

 lateral. The latter is rather small. The malar bone is narrow, and is 

 continuous with the dentigerous bone of the palate. The latter has a 

 thickened posterior edge, which commences below the anterior part of the 

 orbit, and extends posteriorly to the middle of the basisphenoid. Thence 

 the border turns forwards. Its anterior edge is below the anterior border 

 of the orbit, and the general form is a longitudinal oval. The maxillary 

 teeth are somewhat weathered and obscured by a thin layer of matrix. 

 The posterior ones are compressed-conic ; the premaxiUaries are four in 

 number on one side, and are more nearly conic, and have incurved apices. 

 The median premaxillary suture is, however, not clearly defined, so thai 

 the number of premaxiUaries remains uncertain. The centre of the prob- 

 able nostril measures one-third the distance from the premaxillary border 

 to the anterior edge of the orbit. There are eight rows of (?) pterygoid 

 teeth at the posterior fourth of the series. The teeth are subequal and 

 obtuse, increasing a little anteriorly. 



The mandibular ramus is robust, and the external face slopes inwardly 

 and downwards. The external border rises a little above a few of the 

 posterior teeth, but it is injured at the posterior of the coronoid process, so 

 that its existence cannot be ascertained. The border then descends and 

 turns inwards to the articulation, which is condyloid at its internal extrem- 

 ity. The inferior edge of the anterior part of the ramus becomes a median 

 ridge below the condyloid region, and terminates in a short, compressed 

 angular process. The symphysis is not coossified, and is convex down- 

 wards and forwards. The inferior part is subhorizontal, and forms the 

 edge of a transverse plate which is separated from the vertic vl part of the 

 ramus by a deep groove. The inner vertical face of the ramus is strongly 

 convex, as is the corresponding edge of the symphyseal suture. The 

 apices of the teeth are worn, but they were probably conic, the posterior 

 gradually smaller and more obtuse. The interior face of packed teeth 

 begins^at Jhe posterior two-fifths of the external series, and expands in- 



