1S96.] 1^' [Cope. 



definitive of the Pariotichiclfe be the true one, the genus Labidosaurus 

 must be referred to a dilTerent one, and I know of no character at present 

 to separate it from the Pariasauridte of which the known species are so 

 far as known up to the present time restricted to South Africa. It differs 

 from the known genera of that family in the greatlj^ elongate premaxil- 

 lary teeth, and in the simple conic dental crowns. 



Char, specif. — Specimens since received display numerous character- 

 istic peculiarities not preserved in the type. The sculpture of the cra- 

 nial surfaces is in shallow fossae with rather thick partitions, of smaller 

 size than in the Pariotichus aguti, which resembles it most nearly. Thus 

 there are a dozen ridges between the orbits on the front in the latter, 

 while there are fifteen to seventeen in the L. hamatus. The maxillary 

 teeth are relatively smaller than in any of the species of Pariotichus 

 known, and they extend only to below the middle of the orbit. The 

 orbit is subround ; in the type it is oval, perhaps owing to pressure. 

 Its diameter is about half the length of the skull, both anterior and pos- 

 terior to it, and equals the interorbital width. The nostril is anteropos- 

 teriorly oval, and the apex of the elongate incisor tooth is below its 

 anterior part. Thus, though the muzzle is more elongate than in any of 

 the species of Pariotichus, it does not project so far bej'ond the premax- 

 illary border. Length of skull of new specimen 155 mm. 



APPENDIX ON A SPECIES OF TRIMERORHACHIS. 

 Trimerorhachis conangulus, sp. uov. 



Size, the least of the species of the genus. Angle of the mandible 

 produced, conic. Orbits rather large, the posterior border nearer the line 

 of the end of the muzzle than to the posterior extremity of the mandi- 

 bular angle, but not so near as to the posterior border of the tabular 

 bone. External nares half way between orbit and end of muzzle. In- 

 terorbital width equal diameter of orbit. 



Teeth small, the crowns elongate and acitte. Twenty-two may be 

 counted from the posterior end of the series to a point opposite the an- 

 terior border of the orbit. A much larger tooth is situated on the ex- 

 ternal border of the maxillopalatine ("vomer"), a little distance in front 

 of the choanse, while an equally large one is situated directly on the pos- 

 terior border of the latter. Another tooth of equal size is situated ex- 

 ternal to the posterior tooth, near the maxillary border, and the base of 

 a smaller one is visible beneath the two. 



The mandibular ramus becomes quite slender anteriorly-. Posteriorlj^, 

 the sittures of the angular, articular, dentary and splenial, are distinct. 

 The symphysis projects beyond and turns up in front of the premax- 

 illarjr border. The angle projects considerably beyond the quadrate, 

 and is rounded below and at the sides. The extremity is verticalljr 

 grooved, but whether accidentally or normally I cannot determine. 



The elements composing the cranial roof are mostly distinguishable. 



