34 



PISCES 



CLASS I 



of rather doubtful relationships. Most species described under this name 

 referable to Lamna and Odontaspis. Cretaceous and Eocene. 



Lamna, Cuv. Second dorsal fin and the anal very small. Side of tail with 

 keel. Teeth as in Odontaspis, but the principal cusp usually somewhat broader 

 and the lateral denticles 

 larger. Very abundant 

 in the Chalk, Tertiaries, 

 and existing seas. 



Oxyrhina, Ag. (Fig. 

 68). Only differing from 



Fig. 66. 



Otodus appendicu- 

 latiis, Ag. Planer ; 

 Quedlinburg. 



1'h.. 67. 



Otodus obliquus, Ag. External 

 aspect of tooth. Eocene ; Sheppey. 



Fig. 6S. 



Oxyrhina plicatilis, Ag. Mio- 

 cene ; Neudorfl, Hungary. 



Lamna in the teeth lacking lateral denticles. Cretaceous to Recent. 0. 

 manielli, Ag., the commonest Cretaceous species both in Europe and North 

 America, the nearly complete dentition known from Kansas. 0. desori, Ag., 

 chiefly Lower Tertiary ; 0. hasfalis, Ag., 

 chiefly Upper Tertiary. 



Alopecias, M. and H. Tertiary and 

 Recent. 



Cor ax, Ag. (Fig. 69). Known only 

 by low triangular teeth with sharp, 

 serrated edges, and a large root. 

 raon in the Middle and Upper Cre- 

 taceous. C. prist oi I onf us, Ag., from 

 Maastricht, North Africa (F12;. 69), and 



Fig. 69. 



Covax pristodontus, Ag. 

 Upper Chalk ; < >asis of 

 Dachel, Libyan Desert. 



Carcharodon megalodon, Ag. .Miocene; Malta. 



supposed Eocene of Alabama. C.fakatus, Ag., European and North American 

 Cretaceous. 



Carcharodon, M. and H. (Fig. 70). Second dorsal fin and the anal very 

 small. Side of tail with keel. Teeth very large and triangular, with 

 serrated lateral edges, flattened outer face, convex inner face. One Upper 



