8 Bulletin American Museutn of Natural History. [Vol. XIV, 



the Viverravidae ; the Felidse and ? Hysenidae probably from the 

 Palaeonictidae ; the Ursidse either from Arctocyonidae or, with 

 the Canidge, from Viverravidae — as discussed later in this paper. 

 As for the Pinnipedia, it appears to me that there is no evi- 

 dence sufficient to justify our deriving them from any known 

 type of Creodont or Carnivore, and that their ancestors are not 

 very likely to be found in the almost exclusively terrestrial fauna 

 of the fossil beds of the Bad Lands. (See also Osborn, 'oo.) 



II.— Family VIVERRAVID^ Wortman 6^= Matthew. 



Viverravus Marsh. 



Syn., Didyinictis Cope. 



" The lower jaws in this genus are long, very slender and compressed ; the 

 last two molars are tubercular.' Both have the posterior part of the crown 

 quite low and the anterior half elevated and composed of three angular cusps. 

 The four teeth anterior to these '^ are much compressed. The upper flesh 

 tooth closely resembles that in some of the Viverridce, and the genus should 

 probably be referred to that group." — Marsh, '72, p. 7, of separate. 



" Inferior molars six, consisting of four premolars and two molars. True 

 molars, a posterior tubercular and an anterior tuberculo-sectorial, i. e., with three 

 elevated cusps and a posterior heel. Premolars with a lobe behind the principal 

 cusp. Canine teeth directed forward, and close together, so that it is doubtful 

 whether there were any incisors. An ungual phalange of the typical species is 

 strongly compressed. Humerus distally expanded transversely and margin 

 pierced by humeral artery. Astragalus exhibits two entire trochlear faces, the 

 wider external and directed interosuperiorly, the inner presenting superointeri- 

 orly. They are separated by an obtuse longitudinal angle and are little or not 

 at all concave transversely. The form is depressed. The head supports a 

 single transverse convex facet for the navicular, and with the neck is as long as 

 the trochlear portion." — Cope, '84, p. 304. 



A fragmentary skeleton found in the Big Horn Valley by the 

 Princeton Expedition of 1884 was described by Prof. Scott 

 ('87, p. 169) under the name of Didymictis altidens. As this 

 species is not otherwise known to occur in the Wasatch, it is 

 possible that the specimen should be referred to the closely 

 allied V. {D.) protenus. Two somewhat more complete skele- 

 tons found in the Wasatch of the Big Horn Valley by the 

 American Museum Expedition of 1896 further illustrate the 



' Meaning, apparently, with tubercular heel. The context favors this interpretation. Marsh 

 apparently meant at this time to include in the genus forms like Telmatocyon. 

 1. e.y premolars 1-4. 



