» 



Vol. 5] Jordan.— The Fossil Fishes of California. 107 



root, about two-thirds height of crown. Larger teeth with a sharp 

 denticle at base on each side. These are absent in the smaller 

 teeth, which, like an Isurus, has no denticles. Agassiz figures this 

 species as without denticles. 



11. Lamna ornata Agassiz. 



(Agassiz, 1. c. p. 275; Navy Point, Benicia.) 



Of this species, Agassiz figures only a small part of the base 

 of the cusp. This is much more strongly striate than Lamna 

 clavata. I have not seen Larrma ornata. 



Agassiz says of this species that it is smaller than Lamna 

 elcgans of Europe. The tooth "tapers more gradually, while in 

 Lamna elcgans it tapers more suddenly near the top, and the folds 

 of the enamel on the inner side of the tooth ai*e coarser. The base 

 of the tooth is more compressed than the L. elcgans, in which re- 

 spect the tooth resembles more L. acuminata." 



12. Lamna species. 



In a hard sandstone of the Chico formation are two small 

 teeth, one very long and flexuous, another shorter, narrowly tri- 

 angular, with large basal denticles on one side. These belong to 

 a species of Lamna apparently related to the one figured by Mr. 

 Stewart as Lamna appendiculata from the Cretaceous of Kansas. 

 Its basal denticle is very much larger than in Lamna clavata, 

 while the tooth itself is broader and less flexuous. The tooth is 

 sharper and more erect than in Lamna appendiculata. It may 

 be found that this species is referable to Odontaspis. We find no 

 figure which quite corresponds to its form. 



Genus Isurus Eafinesqne. 

 {Oxyrhina Agassiz.) 



13. Isurus planus (Agassiz). 



{ Oxyrhina plana Agassiz, 1. c. p. 275 ; Ocoya Creek.) 



In this genus the teeth are more or less elongated, entire- 

 edged, without basal denticle, the outer teeth much broader and 

 shorter than the others, the median teeth more or less slender and 

 flexuous, suberect, the outer teeth more or less hooked outward 

 and with a knife-like upper edge. On account of variations in 



