1921] Prick: Faunas of Bautista Creek and San Timoteo Canon 353 



Lower jaw referred material. — The lower jaw specimen shown in 

 figiire 59 (Univ. Calif. Coll. Vert. Pal. no. 23370) has been recon- 

 structed from disintegrating fragments which were found held 

 together in crumbling rock. The triturating surfaces of several of 

 the teeth are too far gone for accurate description. is small and 

 tricuspid, and Pj completely molariform, thus resembling the P- of 

 the type upper jaw (no. 23369). The slightly greater proportionate 

 size of the teeth admits of but tentative reference to the upper series. 



A small, newly erupted tooth (Univ. Calif. Coll. Vert. Pal. no. 

 23776, fig. 60) is very similar in form and size to P5 of the lower 

 series (no. 23370). Greatest anteroposterior and .transverse diameters 

 measure 13.7 mm. and 10.3 mm. It is low-crowned and four-rooted. 

 The four rounded main cusps are divided into a posterior and a 

 slightly higher anterior pair, of A¥liich the anterior external corner 

 is broken. Three small accessory tubercles lie respectively at the 

 mid-posterior and mid-anterior extremities, and in the main transverse 

 valley. There is a slight suggestion of cingula in connection with the 

 anterior tubercle and the outer end of the main transverse valley. 



Measurements of Lower Teeth Eeferred to Prosthennops edensis, n. sp. 





No. 23370 



No, 23776 



Po, greatest anteroposterior diameter 



10 mm. 



13.7 mm. 



P3, greatest transverse diameter 



7 



10.3 



P5, height of crown 





8.5 



Pj, greatest anteroposterior diameter 



13 



11. 



Pj, greatest transverse diameter , 



10.3 



6.5 



• Mi, greatest anteroposterior diameter 



13.7 





Mj, greatest transverse diameter 



15.5 





Ma, greatest anteroposterior diameter 



16.0 





Mj, greatest transverse diameter 



11,2 



No, 23775 



M3, greatest anteroposterior diameter 



(27) 





M5, greatest transverse diameter 



13 



13.6 



M5, height of crown 





6.7 



Comparisons. — The lower premolar specimen (no. 23776) lacks the 

 high, paired cones, and the deep, uninterrupted transverse valley 

 of the genus Platygonus. Superficially it somewhat resembles Pr^ of 

 Myloliyus from the Conard Fissure,*" but differs through its much 

 smaller size, and the considerably less pronounced development of 



■so Brown, Barnum. The Conard Fissure, a Pleistocene Bone Deposit in North- 

 ern Arkansas: With Descriptions of Two New Genera and Twenty New Species 

 of Mammals. Mem. Am. Mus. Nat. Hist., vol. 9, pi. 24, 1908. 



