1921] Prick: Faunas of Bautista Creek and San Timoteo Canon 331 



that of the metaeone tends to be convex instead of concave. Drawings 

 (figs. 38a-38&) of the moderately worn triturating surface and of a 

 deep cut section of a referred P-( ?) point to the following characters 

 being due to a certain extent to age : ( 1 ) roundness of the protocone, 

 (2) narrowness and simplicity of the fossettes, (3) absence of the post- 

 protoconal folds. 



The referred lower cheek tooth (figs. 40a-40&) is moderately worn. 

 It is notably small. The groove of the metaconid-metastylid column is 

 sharp but shallow. The wings of the column are moderately elongated 

 and symmetrical. The fold between the protoconid and hypoconid is 



Figs. 41o and 41b. Pliohippus francescana minor, n. subsp. Premaxillary 

 with incisors, no. 23347, X %. Fig. 41a, ventral view; fig. 411), anterior view. 

 San Timoteo beds, California. 



broad and pointed, and does not reach the mouth of metaconid- 

 metastylid. The exterior face of the hypoconid is flattened, while that 

 of the protoconid is rounded. The entoconid is large and oval, as 

 commonly the case in premolars. 



The referred incisors (figs. 410-41?)) are small, evidently belonging 

 to a form not larger than that represented by the upper teeth (com- 

 pare Bautista, fig. 25). 



Measurement of Type and Referred Teeth of Pliohippus francescana minor 



Type Referred Specimens 



No. 2326G No. 23263 No. 23264 No. 23267 No. 23275 No 23274 " 

 P2 Pl Ml Ml P3 Lower tooth 



Anteroposterior diameter 31.8 mm. (26.7)mm. 27 mm. f26.3)mm. 30.3mm. 26.8mm. 



Transverse diameter 29.7 29.4 28.8 29 28.7 15.1 



Length of protocone 10 10.7 10.5 10.7 8.6 



Length of metaconid-meta- 

 stylid column 14.9 



