1898.] Osborn, Evolution of the Atnblypoda. Parti. 213 



C. testis series found in the Middle Wasatch. It appears like a 

 direct successor of Pantolambda eavirictus. 



The median incisors are equal to the others, the lateral incisors 

 being slightly the smallest. The canines have a rounded crown 

 somewhat flattened in front by wear. The superior grinding 

 series present a rudimentary posterior crescent on m^ and an oval 

 m-^- with short oblique ectoloph. The most unique features are 

 the form of the occiput and the cranium as defined above, which 

 is intermediate between that of Pantolambda and Coryphodon 

 armatus. 



The metatarsal V is short and robust (= 42 mm.), with the 

 characteristic peroneus tuberosity of the true Coryphodon. Both 

 femora are finely preserved (length, = 340 mm.), being of the 

 smallest size known. 



Inserts Sedis. 



The position of the following types with reference to the Series 

 I-III, which we have been considering, is uncertain. 



4. Coryphodon radians Cope. 



Type, No. 4300, Am. Mus., Cope Coll. Superior molars i, 2 and 3. Prob- 

 ably associated lower jaw, No. ? 4300. Portions of skeleton. Loc, Evanston, 

 Wyoming. 



Definition. — Third superior molar with a spur (metacrescent) upon the pos- 

 terior crescent of the ectoloph. Third inferior molar without entoconid 2, 

 hypolophid nearly transverse. Lower canines somewhat incisiform. 



This classic species, which rests upon somewhat uncertainly 

 associated upper and lower teeth, jaws and skeleton, was the first 

 described in America. The structure of the last upper molar 

 is shown in Fig. 15. The last lower molar has crests nearly as 

 transverse and simple as in C. latidens. The most distinctive 

 structure is the lower canine which, although badly broken, 

 exhibits a distinct flare at the base of the inner face, as in the 

 incisors, and is apparently becoming incisiform, an interesting 

 approach to Uintatherinm. 



