11G 



University of California Publications. [Geology 



metamorphosed series more like the hard rocks of San Diego, but 

 more indurated." 



I refer to Carcharodon riversi, with some doubt, another tooth 

 collected by Dr. Rivers in Rustic Canon, in the Santa Monica 

 Range, from Pleistocene deposits. The form and the number of 

 serrations are about as in C. riversi, but the serrations are dis- 

 tinctly weaker than in the type of the latter species. This tooth 

 is about one and one-fourth inches high, broadly triangular, the 

 point scarcely incurved. The inner face of the tooth shows six to 

 eight shallow furrows. 



To this species I refer also, with some doubt, four specimens 

 from Barker Ranch, in Miocene deposits. I have also an example 

 from Pliocene deposits on Zapata Chino Creek, Fresno County. 

 These teeth are each about an inch long, being smaller than in the 

 other species of Carcharodon in California. 



This species has thin, flat, straight teeth, narrowly triangular, 

 the base about as broad as the crown is high, and the serrations 

 relatively fine, but few in number ; about thirty to forty on the 

 outer margin. As all these teeth are much abraded, it is possible 

 that the serrre in a fresh tooth would be stronger. 



20. Carcharodon branneri Jordan, new species. 



A gigantic tooth of Carcharodon is in the Museum of Stan- 

 ford University, from near Bolinas Bay in California. This tooth 

 is a little over three inches high, broadly triangular on a broad 

 cordate root ; the base of the crown is a shade greater than the 

 height of the crown. The tooth is moderately thick, and rather 

 strongly retro-curved, as in Carcharodon arnoldi. The edges of 

 the tooth are finely and evenly serrated, the number of teeth 

 being from eighty to one hundred on each side, adding in the 

 count those which are broken off in the type. 



The monstrous Carcharodon megalodon Charlesworth, of the 

 phosphate beds of South Carolina, has one hundred to one hun- 

 dred and twenty serrations, as coarse as in C. riversi, and there is 

 a suggestion of a median ridge on the tooth, which is less curved 

 than in C. arnoldi and C. branneri. 



A fragment, comprising about one-fourth of a giant tooth of 

 Carcharodon, is in the collection of the University of California, 



