442 Wortm an — Stu dies of Eocene Mamm a lia in the 



Comparison with the Viverrines. 



It will be observed from a consideration of the characters 

 detailed above, that Vulpavus approaches the carnivorous 

 civets quite closely in many of the more important features of 

 its osteology. Indeed, it would appear that the interval 

 "between these ancient Canids and the civets is actually less than 

 it is between Vulpavus and the fox. A comparison of Vulpavus 

 with such a form as the living Viverricula or Herpestes 

 reveals the following rather striking resemblances: (1) The 

 postorbital constriction of the skull is considerable ; (2) the 

 superior molars display the same peculiar elongation of the 

 anterior part of the crown and the internal cusp of the 

 superior sectorial is large ; (3) the principal shear of the 

 inferior sectorial is very oblique and there is a distinct posterior 

 shear present which bites against the anterior edge of the first 

 superior molar ; (4) the distal end of the humerus is broad, 

 the supinator ridge is large, there is no intercondylar perforation, 

 and an entepicondylar foramen is present ; (5) the radius is 

 short, the head circular, and there was power of complete pro- 

 nation and supination; (6) the ischial tuberosities are small; 

 (7) the limbs are not elongated ; (8) the feet are pentadac- 

 tyle ; (9) the femur is longer than the tibia, the cnemial 

 crest is elongate, and the fibula is little reduced and not applied 

 to the tibia; (10) the head of the astragalus is placed 

 obliquely upon the body, and the transverse plane of the 

 navicular articulation coincides with the transverse plane of 

 the trochlea ; (11) the hallux is little reduced, the feet are 

 relatively broad and the metapodials are not greatly appressed 

 and interlocking. 



These resemblances would undoubtedly be greatly augmented 

 did we compare the Eocene ancestors of the viverrines with 

 the species under consideration, but notwithstanding these 

 similarities of structure, many of which may be looked upon 

 as primitive characters more or less common to all the early 

 Carnivofa, there yet remain certain unmistakable features 

 which stamp it as belonging to the canine phylum. In the 

 structure of the superior molars as has already been stated, 

 there is a very decided tendency to the formation of a poste- 

 rior internal cusp from the cingulum. Among the Carnivora 

 this is exclusively dog-like and completely unknown in the 

 Viverridse., On the other hand, there is a distinct anterior 

 basal cusp upon the superior sectorial of all the civets 

 wherever this tooth displays the laniary structure, whereas, 

 with one exception it is absent in all the Canidse. The inferior 

 molars are both in number and general structure much more 

 dog-like than civet-like. No viverrine is known in which there 



