MERYCOCHCERUS 



153 



M 3 is much 



the metastyle of M 3 so well developed as in the genoholotype. The hypocone of 

 reduced in comparison to the size of the protocone. The molar-premolar index is 0.71 . 



Inferior: The degree of complication of the premolars is close to that of M. proprius but 

 corresponds to that of the superior series. Pi is relatively smaller. The internal cingula are strong, 

 while the external ones are moderately marked. The molars are moderately hypsodont, with faint 

 external ribs on the metaconid and entoconid columns. The metastylid of M 3 is proportionally 

 much reduced. 



^mm 



SsiJif \ 



Fie. 112. — Merycochcerus buzvaldi Merriam. Fragmentary skull and superior dentition. 



2/3 nat. size. (After Merriam, 1919.) 



HT. Cat. No. 21350 U.C.M. 



Discussion: Gazin (1930, p. 73) described a fragment of a ramus, Cat. No. 56 U.C.M. , which 

 resembles in size Cat. No. 21487 U.C.M., a paratype of the above-described species. It consists of 

 the posterior portion of a lower jaw, with only the tooth roots remaining, and is therefore indeter- 

 minate. It was collected in the vicinity of Apache Canyon, in the upper Cuyama drainage basin, 

 Ventura County, California. The Cuyama horizon is probably middle Miocene, although the fauna; 

 of this zone compare most favorably with that of the Barstow. 



Merycochcerus ccenopus Scott 1890 

 PI. XXXI, figs. 3-4 



Original Reference: Beitrage zur Kenntniss der Oreodontidne. Morphologisches Jahrbuch, Bd. XVI, 

 pp. 346-347, pi. XVI, figs. 33-34. 



Type Locality: Near the head of Wolf Creek, a tributary of the Niobrara River, Nebraska. 



Geologic Horizon: Lower Pliocene (Valentine). 



Type: Holotype, Cat. No. 9156 M.C.Z., distal end of ulna and most of manus and pes. Collected by 

 Samuel Garman in 1882. 



Specific Characters: The ulna is as strong as it is in Merycoidodon. The tibia* shows no 

 peculiarities. The fibula* is much reduced, with the medial section consisting of a thin bone thread, 

 which perhaps was interrupted. This differs from the fibula of M. proprius, in which the middle 

 third of the shaft has a prominent crest projecting anterointernally toward the tibia. In other 



* The tibia and fibula have been temporarily misplaced, and this information concerning them is taken from 

 Scott's original description. 



