Vol. VII, pp. 151-158 July, 1892 



PROCEEDINGS 



OF THK 



BIOLOGICAL SOCIETY OF WASHINGTON. 



ON CARCHARODON MORTONI GIBBE8.* 

 BY F. A. LUCAS. 



In his Monograpli of the Fossil Sqiialidte of the United States 

 Gil»l)es assigns the name Carcharodon mortoiii to two incomplete 

 teeth, stating that with the exception of a single specimen in the 

 cahinet of F. S. Holmes, of Charleston, he had met with none 

 elsewhere. The si)ecies was originally descrihed in the Proceed- 

 ings of the Academy of Natural Sciences of Philadelphia for 

 1847, page 266, the descriptions heing rejDeated in the .Journal 

 of the Academy for 1848, page 146, and one of the specimens 

 shown in figure 45, plate xxi. 



The essential part of the description consists in the statements 

 that " both the outer and inner surfaces are convex and promi- 

 nent, the latter trebly so," and " the root is innnensely thick, an 

 incli and a half, and constitutes more than half the ])ulk of the 

 tooth." The figvire shows the tooth to have been unusually 

 thick and swollen for a tooth of Carcharodon, and that the root 

 was irregular in shape. 



A. Smith Woodward, in his Catalogue of Fossil Fishes in the 

 British Museum, places Carcharodon mortoni, with scA^eral other 

 reputed species of the genus, in the list of those "'* * * recog- 

 nized upon the evidence of detached teeth, tliough it is not 

 improbable that some of the names are svnonyms ''^ * *." 



* Read before the Biological Society of Washington, Feb. 20, 1892. 



21-Bior.. Sue. Wash., Vol. VII, 18J2. (151) 



