16 



FOSSIL FISHES. 



Sandalodus, from the Carboniferous Limestone (Table-case 29), 

 had probably only one very large tooth on each side of its upper 

 and lower mandibles, or four in all. 



TEETH OF SUAKKS. 



Fig. 19. — Tooth of Lamna elegans, 

 Agassiz, London Clay. 



Fig. 20.— Tooth of Carcharodon meyalodon, 

 Agassiz, Suffolk Crag. 



The Carcliariidce, Lamnidce (Fig. 19), and Notidanidce, characterize 

 the Cretaceous and Tertiary formations. A fine series of the teeth 

 of these sharks is displayed in Table-cases 26 and 27. 



Noteworthy amongst these are teeth of the genus Carcharodon 

 (Fig. 20), Table-case 26, which greatly exceed in size those of any 



Fig. 21.— Jaws of Male (A) and of Female (B) Skate, Raja clavata, showing the remarkable 



variation in the dentition which they exhibit. 



living species of Shark. They are very widely distributed, being 

 met with in Tertiary strata in New Zealand, Jamaica, S. Carolina, 

 in Egypt, Malta, and in the Antwerp and Suffolk Crags. 



It is interesting to notice that in some places, both in the Atlantic 

 and Pacific (especially at extreme depths in the red-clay areas), the 



