PLATE XIII. 



Figs. 1-40. — Corax falcatus Agassiz, about nine-tenths natural size; isolated 



teeth from many individuals. 

 Figs. 41-46, 50-52. — Oxyrhina mantelli Agassiz, nearly natural size. 

 Figs. 47-49. — Lamna aiDpendiculata Roemer, nearly natural size. 

 Fig. 53. — Ptj/choclus, sp., enlarged one-fourth. 



