Peterson: Uinta Titanothere Dolichorhinus. 



185 



two genera in more detail, it is seen that there is a less developed 

 tubercle on the outer margin of the tendinal groove of the olecranon 

 process in Dolichorhinus than in DipJoceras. In consequence the 

 groove is not as well defined in the genus under description, though the 

 termination of the olecranon process is fully as well developed. In 

 Dolichorhinus there is a greater constriction of the /" 



olecranon between the upper border of the great ' ^ 



sigmoid notch and the termination of the process 

 than is seen in Diploceras. Otherwise the ulna is 

 quite similar in the two genera. 



The Maniis. — The manusof the specimen under 

 description is complete with the exception of the 

 ungual phalanges and the proximal phalanges of 

 digits III and IV, which were not recovered. 

 The foot as a whole is short and broad, and, when 

 compared with the manus of Diploceras, it may be 

 said to be heavier. In comparing the 

 carpal elements of the two genera it is 

 at once observed that they are all of 

 greater height in the present genus 

 than in Diploceras, which indicates 

 that the latter genus was already well 

 advanced in the direction of the low 

 and broad carpals of the Oligocene 

 Titanotheres. The distal ulnar angle 

 (the articulation for the magnum) of 

 the scaphoid of Dolichorhinus is pro- 

 duced more downwards, but is of 

 smaller size than in Diploceras. The 

 region of the upper facet for the lunar 

 on the ulnar face is also more over- 

 hanging in the ulnar direction than in 

 Diploceras, this is especially noticeable 

 if the scaphoid of Dolichorhinus and 

 that of the Titanotheres of the Oligocene formation in the Carnegie 

 Museum are compared. The lunar has a rather unusually broad 

 contact with the unciform and a narrow and more nearly vertically 

 placed facet for the magnum. A third feature of the lunar is the 

 limited posterior extent of the facet for the unciform, and the lack of 



'■^ 



Fig. 6. Right fore limb of Doli- 

 chorhinus longiceps (?), No. 2865, H 

 nat. size. 



