the McD'sh Collection. 397 



than incisors. P^ apparently permanent, partly erupted, 

 but unused, compressed, trenchant. Dp.,., present. Dp4 

 three-lobecl, otherwise molariform. Mj the only erupted 

 molar. 



Eamus very slender, gracefully curved, symphysis long. 

 Mental foramen of left side just below anterior margin 

 of Pj. This form differs from Poebr other ium chiefly in 

 the great elongation and attenuation of the muzzle, giving 

 an actually greater antero-posterior dimension to the 

 premaxillaries and a relatively slenderer jaw and longer 

 symphysis. The lack of caniniform teeth is evidently 

 due, in part at least, to the permanent ones not having 

 erupted, and the diastemata are relatively much greater. 

 While the nasals are not preserved throughout their 

 entire length, it is doubtful whether they ever extended 



/oo^o, Y. p. M. 



Fig. 3. — Taratylopus cam.eloides (Wortman). Juvenile. Palatal aspect 

 of skull. X 3/5. 



SO near the tip of the muzzle as in Poehrotherium, 

 although their relative extent, as compared with the 

 maxillaries, was similar. 



The lower jaw, on the other hand, has very much the 

 contour of the type of Paratylopus cameloides, with which 

 it also agrees in the lack of diastemata between the lower 

 incisor and canine teeth. The position of the mental 

 foramen also is in practical agreement, although it varies 

 in the two rami of the jaw, extending further back on the 

 right side. The size of the permanent molars approxi- 

 mately corresponds. 



Two other specimens may be referred to Paratylopus 

 cam.eloides. These are, first. Cat. No. 10917, Y. P. M., 

 collected by William Day in 1875 from the upper John 

 Day beds at the Cove, John Day River, Oregon, and con- 

 sisting of the superior maxillary, containing the dentition 

 from the canine back, except that the crowns of P^"^ are 

 broken away. This is an old animal, with M^ worn almost 



Am. Jour. Sci. — Fifth Series, Vol. I, No. 5.— May, 1921. 



27 



