60 



THE merycoidodontim: 



vaulted. The moderately convex glenoid articular surface is bounded by the postglenoid process, 

 which is anteroposteriorly narrow and transversely wide and has an oblique external border. 

 Index: 0.58. 



Foramina: The infraorbitals lie above the interval between P 3 and P 4 , while the supraorbitals, 

 1 7 mm. apart, have very distinct channels running forward and downward to the infraorbital fora- 

 mina. The foramen ovale is large and the foramen rotundum unusually large. The posterior 

 palatine foramina are opposite P 4 . 



Z2752 TYPE 

 T.P.AJ. 



Fig. 26. — Merycoidodon flatycephalus Thorpe. Right half, superior view of skull. HT. Cat. No. 12752 Y.P.M. 



2/3 nat. size. (After Thorpe, 1921.) 



Fig. 27. — Merycoidodon flatycefhalus Thorpe. Right half, inferior view of skull. HT. Cat. No. 12752 Y.P.M. 



2/3 nat. size. 



Dentition: The teeth are much damaged, but the alveoli of those missing may be clearly dis- 

 cerned, except those of the incisors. The remaining teeth are very much worn, but a marked char- 

 acter is the considerably smaller size of the hypocones in relation to the protocones of all of the 

 molars. This is especially noticeable in M 3 . These lobes are proportionally smaller than in any 

 other species of this genus. The superior molar-premolar index is 0.93. 



Skeleton: The distal end of the radius shows that the facets for the scaphoid and lunar bones 

 are separated by an interval of somewhat more than 1 mm., which is an unusually large gap for this 

 genus. 



Discussion: Any species based upon a single specimen is bound to have a more or less equivocal 

 status until confirmed by more material. The holotype skull is that of an old individual, as evi- 

 denced by the closed sutures and the high degree of wear on the teeth, which might suggest that 

 these specific characters are due to senility. This may be the case, but I have not seen any skull 

 among many of comparable age which shows the same form. The rugosities might be suggestive of 

 a male, but it would still be of a new race, or at least of a subspecies, as the low, wide skull, the 

 teeth, the size and shape of the orbits, and other characters are very unlike any of the other species 

 so far described. 



There is no sign of injury suffered during life, and, if the thickening of the postorbital 

 processes of the frontal s and of the sagittal crest and temporal ridges is due to disease, the skull is 

 bilaterally symmetrical to so complete a degree that it makes a pathologic explanation seem rather 

 remote. 



