308 THE WASATCH AND BKIDGER FAUN^. 



The tubercular molar is relatively small in this species, not exceeding 

 the average size of that of D. jyrotenus, while the sectorial is considei-ably 

 larger. The anteroposterior diameter of the fourth premolar is equal to 

 that of the sectorial, and that of the third premolar is a little less. The 

 premolars are closely placed, the first not seen. 



The fourth premolar is not much widened posteriorly, and the lobe of 

 the posterior edge is well marked. The cuspidate part of the sectorial is 

 about equal in anteroposterior diameter to the length of the heel. The 

 external cusp is much higher than the two interior, and the latter are equal 

 in elevation. They are all obtuse, as are the continous edges which repre- 

 sent the blade of the sectorial tooth of a higher carnivore. The length of 

 the heel from the base of the internal tubercle is equal to the height of the 

 latter. It carries a ridge-like tubercle, which extends from its posterior 

 external border forwards and inwards. Between its inner side and the inter- 

 nal rim of the heel is an "oblique concavity. The tubercular in its details 

 is a reduced copy of the sectorial, the anterior cusps being represented by 

 low tubercles and occupying relatively very little space. The posterior 

 oblique tubercle and concavity are there. The crown differs from that of 

 the sectorial in having the external basal cingulum stronger ; there is no 

 internal basal cingulum on either tooth. No internal, and a trace of exter- 

 nal cingulum on the fourth premolar. 



The mandibular ramus is compressed and deep. The masseteric fossa 

 is well defined below as well as anteriorly. There is a well defined area 

 of insertion (? for the internal pterygoid muscle) on the inner side of the 

 base of the coronoid process. 



Measurements. 



No. 1. 



u. 



Length of bases of last five inferior molars O^SO 



_. , -. _.. , ( aiitiTopoHlcrior 0150 



Diameters of fourth premolar < ,v^.- 



( trausviTso OOOo 



rv- . r »i 1 < uiitiToiiostorior 0145 



Diameters first tme molar < n,, ^ 



( (ransvcrsc W)9K) 



T-v- » ,^ , ( aiitfriipoMtfrior '-"Os^ 



Diameters secoml true molar I ' nivo 



< Ir.iiisvrrso uuo.: 



Depth ramus ot second tme molar 0250 



