250 V niversity of California Publications in Geology [Vol. 7 



Family LAMNIDAE 

 Genus Lamna Cuvier 



12. Lamna ornata Agassiz. 



Navy Point, Benicia. 

 We know nothing of this species. 



13. Lamna appcndiculata Agassiz. 



Two teeth, from hard Chieo sandstone, are rather long and 

 flexuous. According to Dr. Jordan, "These belong to a species 

 of Lamna apparently related to the one figured by Mr. Stewart 

 as Lamna appcndiculata, from the Cretaceous of Kansas." It 

 is, however, doubtful whether this can be the same species, as 

 there was no geographical connection between the California 

 and Kansas seas during the Cretaceous time. 



The large tooth is slender and tapering with sharp, knife-like 

 edges, the altitude measuring about twice the width at the base 

 of the root. The other standing next to it in the jaw is much 

 smaller but similar. This specimen has no basal denticles, which 

 are so characteristic of the larger tooth. 



Mr. Harold Hannibal has collected from the Eocene Arago 

 formation of Cape Gregory, Oregon, a tooth of this same genus 

 but perhaps of a new species. It is a little higher compared 

 to the width than the preceding species, sharper and more 

 flexuous, and there are minute striations extending from near 

 the point of the crown to the root of the tooth. This tooth has 

 a basal denticle. 



Genus Isurus Rafinesque 

 (Oxyrhina Agassiz) 

 1-1. Isurus hastalis (Agassiz). 



(Oxyrhina plana Agassiz, loe. cit., p. 27-4. Oxyrhina tumula 

 Agassiz, loc. cit., p. 275. Isurus smithii Jordan, loc. 

 cit., p. 111.) 



Miocene of Kern County, San Diego County, and Fresno 

 County. 



Teeth of a giant species of Isurus are excessively common in 

 Miocene deposits of Kern County, far outnumbering all other 



