104 



University of California Publications. [Geology 



specimens belong to Agassiz's species. They are broader than 

 shown in Agassiz's figures, more erect and more strongly serrate. 

 Possibly Agassiz's figures were drawn from teeth from nearer the 

 side of the jaw. 



7. Carcharias species. 



A tooth which I am unable to place is broadly triangular, 

 thick and blunt with a broad base, longer on the outer margin. 

 The crown is convex anteriorly, and flat behind. The tooth is 

 everywhere very coarsely serrate, eleven teeth on the outer mar- 

 gin of the crown, about eight on the inner margin, and six on the 

 expanded base. It is about 14 inch in height, and was found in 

 the lower Miocene near Oil City. 



Agassiz figures nothing like it. It is perhaps a lateral tooth of 

 some species of Carcharias having the teeth much more strongly 

 serrated than is the case in C. antiquus. 



A second specimen from Barker Ranch seems to belong to 

 the same species. It is larger, rather narrowly triangular, sub- 

 erect, flat on the posterior side, and with the edges rather strongly 

 serrate. The root is lost. 



Genus Hemipristis Agassiz. 



8. Hemispristis heteropleurus Agassiz. 



(Agassiz, 1. c. p. 274; Ocoya Creek.) 



Of this genus, Agassiz had a single tooth from Ocoya Creek. 

 He separates the species from Hemipristis serra of the European 

 Tertiary by ' ' the marked inecpiality of the serration of the hinder 

 margin when compared with that of the anterior margin of the 

 tooth." This difference, as Agassiz indicates, is a very slight one r 

 and in fact we doubt if it exists, and there is no obvious reason 

 for regarding the California species as different from Hemipristis 

 serra. 



In Mr. Anderson's collection, in the Museum of the California 

 Academy of Sciences, are two specimens of this species from the 

 "Northwest of Barker Ranch on the Kern River," and one from 

 near Oil City. The largest is nearly an inch high, the other- 

 shorter. In this genus the teeth are erect, strongly curved out- 

 ward, both margins rather convex, with a slight reentrant angle: 



