28 AMERICAN PERMIAN VERTEBRATES 



squamosal, very clearly distinct from the small quadra to jugal 

 on the lower posterior margin, but not distinguishable at present 

 from the postorbitals and epiotics quite to my satisfaction. Back 

 of the parietals are the narrow transverse dermoccipitals, which 

 seem to be quite distinct from a small bone at the outer angle, 

 which doubtless is the tabulare (epiotic). The structure of the 

 posterior part, the occipital region, is somewhat confusing, and 

 I do not feel at all sure of my determinations. The discussion 

 of this region I reserve for a later paper, hoping that additional 

 material may be forthcoming. The structure of the palate, so 

 far as it has been developed in the specimen, is most interesting, 

 so closely resembling the " rhynchocephalian " type that a few 

 years ago, had it been found without other parts of the skull, it 

 would have unhesitatingly been located in the "Diapsida" and 

 "Diaptosauria." The specimen has not yet been thoroughly 

 cleaned in the anterior part, so that I can say nothing of the vomers. 

 The palatines and united pterygoids are, as in Labidosaurus and 

 Pariotichus, separated by a more or less elongated interpterygoidal 

 space. The eminence in the region of the transverse, if the bone 

 be distinct, as I think it is, is crowned by a row of five or six teeth, 

 evidently more or less conical in life, but unpreservable in the 

 preparation of the skull. In front of these teeth I can find evidence 

 of but a single tooth, located as I have marked; I am not quite 

 sure of it, but in all probability there were others. Opposite the 

 front end of the basisphenoid, the pterygoid on each side articulates 

 with a stout basipterygoid process of the basisphenoid, quite as 

 in the lacertilians, the first evidence I have seen among the Permian 

 vertebrates of a real articulation at this place. The pterygoid has 

 a pit or depression on the inner side for the head of this large pro- 

 cess. Back of these processes the pterygoids resemble remarkably 

 the like processes of the lizards, a not very wide, rather stout, 

 obliquely placed process reaching backward to articulate with the 

 lower inner side of the quadrate. In the middle the large basisphe- 

 noid is conspicuous; unlike that of the Diadectidae it is stout and 

 rounded below, where it gives off the basipterygoid processes. 

 Anteriorly it gives off the so-called parasphenoid. But the " para- 

 sphenoid" in this case is a thin vertical plate, thickened poste- 



