Marsh Collection, Peabody Museum. 147 



species are distinct and we have the anomalous condition of 

 the latest known species of the genus being less specialized in 

 this particular than its immediate predecessor. The sjDecies is 

 distinguished from all the others bj its small size and the 

 short broad heel of the lower sectorial. The principal meas- 

 urements of the type are as follows : 



Length of inferior molars and premolars 28* mm 



Length of inferior molars 9-5 



Length of sectorial 5-2 



Transverse diameter of sectorial 3 '4 



Antero-posterior diameter of superior sectorial, 7* 



Transverse diameter of superior sectorial 3'5 



The type specimen was found at Grizzly Buttes, by G. G. 

 Lobdell ; other specimens were obtained at various levels from 

 the upper to the lower part of the horizon. 



Viverravus minutus sp. nov. 



This species is represented in the collection by remains of at 

 least six individuals, of which the lower jaws alone, in varying 

 degrees of completeness, are preserved. That which is here 



21 



Figure 21. — Left lower jaw of Viverravus minuius Wortman; outside view; 

 three times natural size. (Type.) 



selected as the principal type, figure 21, is a left ramus carry- 

 ing the molars and the three posterior premolars in good pre- 

 servation. The specimen in question is broken just posterior to 

 the base of the coronoid and also in front in the region of the 

 symphysis, but it includes the base of the canine alveolus as 

 well as that for the first premolar. The crowns of the molars 

 are somewhat worn, so as not to display very clearly the char- 

 acter of the cusps of the heels. On this account, I associate 

 with it another specimen as a cotype, also a left mandibular 

 ramus of the left side, in which the heels of these teeth are 

 more perfectly preserved. A third fragment of a jaw carries 

 the canine in perfect condition. 



