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University of California Publications in Geology [Vol. 13 



P- is subtriangular in horizontal section with the anterior side 

 subacute, thus differing slightly from Leidy's specimens from Ken- 

 tucky. Two cusps are developed on the crown, the inner one of which 

 is somewhat the larger. A well defined cingulum is present, which is 

 especially prominent on the postero-external side and is absent only at 

 the base of the inner cusp. 



P- is subquadrate with two cusps of nearly equal size. An incipient 

 tubercle is present immediately behind the space between the two cusps. 

 A cingulum is strongly developed around the entire tooth. 



P- is shaped much as in P. compressus. Two nearly equal cusps 

 are present on tbe crown with a tubercle, behind their interspace, 

 slightly stronger than on the crown of P 5 . This tooth is little worn. 

 The structure of the crown of the tooth closely resembles that in P. 

 compressus and in P. leptorliinus. 



Mi is much worn. No cingulum is present on the inner side of 

 both protocone and hypocone, and this is true also for the two posterior 

 molars. In M- a well developed cingulum is present along the anterior 

 border. This ledge is more prominently formed along the posterior 

 base of the hypocone than in the corresponding tooth of P. leptorliinus. 



In M- the anterior pair of cusps is larger than the posterior pair 

 and the anterior transverse ridge is wider transversely than the pos- 

 terior one. A cingulum is strongly developed along the anterior border 

 and along the outer posterior border from the paracone to the hypocone. 



Measurements of Skull 

 Length measured from anterior end of premaxillaiy to anterior margin 



of foramen magnum a255 mm. 



Length of palate 181 



Length of anterior end of canine tuberosity to posterior margin of 



infra-orbital fossa 84 



Vertical height from palate to top of skull, measured at posterior 



margin of infra-orbital fossa 82.7 



Vertical height from palate between canines to top of nasals 50.5 



Width across glenoid fossae al28 



Width across postorbital processes a88 



Width at middle of zygomatic arches al24 



Width of face at posterior margins of infra-orbital fossae 46 



Width of snout above M- 44 



Width between outer walls of canine alveoli 73 



Width of palate measured between postero-internal roots of M 1 23 



Width of palatal portion of palatine immediately behind M- 18.5 



Width of premaxillaries at anterior end 38.5 



Dorso-ventral depth of orbit a36.7 



Greatest depth of zj'gomatic arch below orbit 41.7 



