302 



others by Dr. George M. Sternberg, United States Army, from the vicinity 

 of Camp Supply, on the North Canadian River, Indian Territory, probably 

 from a formation of Cretaceous age. 



Their apparent specific identity with the teeth of Galeocerdo falcatus of 

 Europe is seen by comparing the figures with Fig. 43, taken from a tooth 

 imbedded in a block of chalk from Sussex, England. 



Figs. 32 to 36 represent a series of similar teeth obtained, with many others 

 of the same character, by Dr. William Spillman, from near Columbus, Mis- 

 sissippi. 



Figs. 37 to 40 represent smaller teeth, which I suspect to belong to the 

 same species, found by Dr. John L. Leconte, about three miles east of Fort 

 Hays, Kansas. Similar specimens were also obtained by Dr. Hayden, in 

 bed No. 2 of the Cretaceous rocks, near the mouth of Vermilion River, 

 Kansas. 



Figs. 41, 42 represent small teeth, likewise of the same species, obtained 

 by Dr. Shumard from the Cretaceous Ibrmation of Texas. 



OXYRHINA. 



The teeth of Oxyrhina have a simple, compressed demiconical crown, with 

 sharp borders, and without lateral denticles. 



OXYEHINA EXTENTA. 



Figs. 21 to 23, Plate XVIII, represent specimens of teeth of an Oxyrhina 

 discovered by Dr. George M. Sternberg, United States Army, in the vicinity 

 of Camp Supply, on the North Canadian River, Indian Territory. Figs. 24, 

 25 represent similar teeth found by Dr. William Spillman in the Cretaceous 

 formation near Columbus, Mississippi. These teeth differ especially, from 

 those of other species previously described and figured, in the greater pro- 

 portionate extension laterally of the base of the ci-own. They most nearly 

 resemble the teeth of the Oxyrhina Mantelli of the chalk of Europe. 



In the Museum of the Academy of Natural Sciences of Philadelphia there 

 is a specimen of an Oxyrhina tooth in a block of chalk from Sussex County, 

 England, resembling those just described in the unusual extension laterally 

 of the crown. If this specimen pertained to O. ManteMi, it is probable that 

 the specimens from Mississippi and the Indian Territory do likewise. It 

 was not until after I had described the latter under the above name that I 



