54 



In the collections are a few teeth that cannot be distinguished from the one figured 

 by Leidy in the latter of the above two publications. Of these, an average specimen is of 

 the same size as the type and has the same number of serrations. As the crowns of some 

 are worn the exact number of serrations that the tooth had originally cannot always be 

 ascertained. Their sides are smooth. They seem to vary little in form but are proportio- 

 nately thicker, near the base of the crown, than the type. 



Belly Eiver series, Red Deer river below Berry creek, 1901. 



Pal^oscincus aspeb. Sp. nov. 



Plate XVII, fig. 5. 



The tooth for which the above name is proposed is in the form of a laterally com- 

 pressed cone, with a serrate edge and rugose sides. The root was evidently cylindrical 

 but has been broken off close to the base of the crown. 



One side of the crown is more rugosely striated and flatter than the other which is 

 decidedly convex. The trenchant edge has eighteen serrations, fifteen only of which are 

 seen in a side view, as the last three on the right (as figured) are paired with three others 

 of equally small size. The groove separating these three pairs is deep and decided. The 

 other end of the tooth is flattened in an almost vertical direction ; here the serrations 

 curve toward the side of the greater rugosity. The broad apical denticle is the one that 

 shows the most wear. The base of the crown is evenly rounded below to meet the 

 fang. 



This tooth differs materially from others of the genus described by Leidy and Marsh. 

 The serrations are more numerous, the sides more conspicuously ridged, whilst the double 

 row of denticles at one end of the cutting edge, besides being novel, is most interesting 

 and instructive, in that it is suggestive of a progressive step toward the development 

 of a double row of tubercles such as is found in the molars of the Multituberculates. 



The specific name here suggested has reference to the rough sides of the crown of 

 the tooth. 



Measurements. 



M 



Height of crown -0055 



Length of same '006 



Maximum breadth near base '003 



Belly Eiver series, below Berry creek, 1901. 



