Cyclopidiiis (Pithecistes) Cope, etc. 4:13 



Pithecistes was established by Cope on a lower jaw in 

 which, he said, Pi and all of the incisors except I3 had 

 been lost. Likewise the true canine was no longer incisi- 

 f orm, but had again become caninif orni. These characters 

 were shown only in the type species, P. hrevifacies, which 

 was a very old individual. In 1899 Matthew showed 

 that this genus was not valid. He wrote (p. 73) : 



"Careful comparison and more complete removal of the matrix 

 show that: (1) the alveoli of two small incisors are present on 

 each side; (2) the canine, mistaken by Cope for an incisor, is 

 present and worn to a stump; (3) the first premolar, mistaken 

 for canine by Cope, is present and caninif orm; (4) there are no 

 distinctions whatsoever from Cyclopidiiis simus except those due 

 to age of the individual. Pithecistes decedens is the permanent 

 and P. heterodon probably the milk dentition of a smaller species 

 of Cyclopidius; both are founded on upper teeth. ' ' 



I do not think it possible that in this family any form 

 will be found in which Pj has been lost and the true infe- 

 rior canine become caninif orm. This caninif orm pre- 

 molar has developed far in excess of the other premolars, 

 and at the expense of the true canine, in all of the pre- 

 ceding genera of the Oreodontidse. It is possible, how- 

 ever, that a form may be found without any incisors, 

 either superior or inferior, a condition which has occurred 

 in other groups. 



Cyclopidius lulliamis, sp. nov. 



(Figs. 1-3.) 



Holotype, Cat. No. 10117, Y. P. M. Spanish Mines, Wyoming. Lower 

 Miocene (lower Harrison beds). 



The type material consists of a skull and jaws, excel- 

 lently preserved with the exception of the left zygoma 

 and a portion of the left side of the cranium. It was 

 collected in 1908 by Professor Eichard S. Lull, after 

 whom the species is named. 



Specific Characters. — This is the largest species of the 

 genus, and shows remarkably well the generic characters. 

 Its specific peculiarities are very marked. The skull 

 length is approximately that of a small Oreodon culhert- 

 sonii. The muzzle is short, and the zygomata much 

 expanded. The nasal bones are very narrow, expanding 

 anteriorly at the junction with the premaxillaries, which 

 are small. The facial vacuities are very large. A 

 shallow forward-facing depression represents the lacry- 



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



28 



