342 Wortman — Studies of Eocene Mammalia in the 



ber of the Canidge, and the name Vtdpavus was most happily 

 chosen, since it is not only the forerunner of the foxes in name 

 but is so in fact. 



Like most of the Canidse the crown is composed of two 

 principal external cusps, a large lunate internal ridge enclosing 

 a central depression or valley, together with a more internal 

 and posterior ledge-like elevation arising from the cingulum. 

 The external portion of the crown is very different from the 

 corresponding part of this tooth in any of the Miocene, Plio- 

 cene, or modern species of dogs, but resembles that of the 

 great majority of the older and contemporary Creodonts. This 

 consists in its external expansion, and the formation of a rela- 

 tively broad shelf-like area between the external margin of 

 the crown and the two external cusps. Associated with this 

 is the drawing out of the external angles, both anterior and 

 posterior in this species, and the disposition to form cutting 

 blades of these parts of the crown. While the antero-external 

 part of the tooth is broken away in the type specimen, there 

 can be little doubt, from its great similarity in structure to the 

 nearly related species described below, that this angle was 

 present and prominent. 



Of the two external cusps, the anterior is by far the larger 

 and more prominent, and as this character appears to be con- 

 stant in all the species thus far known, it may be taken as of 

 generic significance. The crescentic ridge thickens consider- 

 ably at its internal angle into a low, stout, more or less trihedral 

 cusp which forms its most prominent part. External to this 

 the ridge is interrupted by two, less prominent, anterior and 

 posterior intermediate cusps situated about midway of the 

 tooth crown on the respective borders which they occupy. 

 The posterointernal cingular cusp is unusually broad and 

 thick for such an early species of the Canidse, in fact almost 

 equaling in this respect some of the modern species. The 

 summit of this cusp is closely connected with the cingulum 

 which is developed around the entire crown. 



The locality of this specimen, which is the only one in the 

 collection, is Grizzly Buttes. This locates it near the base of 

 the horizon ; it was found by Professor Marsh. 



The following measurements are given : 



mm. 



Transverse diameter of posterior part of crown 8 



Antero-posterior diameter in middle of crown 4*5 



Vulpavus Hargeri sp. now (Plate V.) 



Two specimens of this species, which include a considerable 

 part of the skeleton, are contained in the collection. From 

 these a fairly accurate knowledge of a large part of the 



