590 S. W. WILLISTON 



sharp, the phalanges well formed. All the bones of the skeleton 

 are very hollow. 



Upon the whole the present animal must be a remarkably long- 

 legged and long-tailed reptile, probably eighteen inches or more in 

 length. 



There are several small reptiles from the American Permian 

 of which we yet have no published knowledge of the extremities, 

 such as Isodectes, Helodectes, and Pariotichus sens, str., the most of 

 which are at once eliminated from comparison with the present 

 genus by reason of their roofed-over skulls. Tomicosaurus Case, 

 described from a fragment of a mandible and several arches of 

 vertebra differs in being a larger animal, and in the character of the 

 teeth, as described by Case. The front teeth neither in the upper 

 nor lower jaws are elongated or incisiform. Nothing is shown in 

 the figures of the diapophyses. The two small vertebrae upon 

 which the genus and species Emholophorus fritillus Cope were 

 founded differ materially from those of the present genus. As to 

 its ordinal position, nothing definite can be said of Araeoscelis 

 till the skulls have been cleaned and studied, and possibly not even 

 then, save of the presence of a temporal vacuity. To locate such 

 a genus in the same group with Dimetrodon or Naosaurus seems a 

 bit absurd. 



Casea broilii, genus and species new. 



The material upon which the present genus and species are 

 based comprises, probably, several complete skeletons found asso- 

 ciated with skeletons of Varanosaurus and Cacops.^ The com- 

 plete working out of the material may require a year or more. The 

 characters are, hence, drawn from those parts of one skeleton now 

 prepared, comprising the larger part of a tail, the sacrum, two 

 lumbar vertebrae, pelvis, and the complete hind legs. I take 

 pleasure in naming the genus and species after Doctors Case and 

 Broili, who have extended our knowledge of the American Permian 

 fauna so materially. 



The chief character wherein the present genus differs from all 

 hitherto known Permian reptiles of America is found in the ilium, 



I Bull. Geol. Soc. Amer., XXI (1910), 249-85, Pis. VI-XVI. 



