204 DESCRIPTION OF FISHES. 
Carcharodon heterodon. (Tab. XI. fig. 19.) 
The finely enamelled tooth of this species agrees so well with M. Agassiz’s de- 
scription as to leave no doubt as to its identity. The teeth are strongly serrated 
and curved in the lower jaw; in the upper jaw they are straight. I have figured 
a tooth from each jaw; the lateral or accessory lobes are more coarsely serrated 
than the body of the tooth. In Mr. Keele’s cabinet at Southampton there are 
several teeth of this species which were found in that vicinity. 
Otodus obliquus. (Tab. X. figs. 32, 33, 34, 35.) 
These teeth are very common at Sheppey, where they occur of a much larger 
size than at Bracklesham ; I have one large specimen from Bognor. 
Otodus lanceolatus. (Tab. XI. figs. 20, 21.) 
The tooth figured agrees in so many respects with M. Agassiz’s description of 
this species, that I retain for it his name lanceolatus ; it is however thinner and 
rather more lanciform in its character. 
Vertebre (Tab. X. figs. 24, 25, 26, & 27) of fishes. I have never seen more 
than three or four in one mass ; when first found they are very soft and fragile 
and require great care for their preservation. The largest vertebra of a shark 
which [ have seen is in Mr. Bowerbank’s collection, and measures nearly 3 inches 
in diameter. 
Order OSSEI, Cuvier, GANOIDEI, Agassiz. 
Genus Silurus. 
Tab. XI. fig. 11 exhibits part of the scapular arch with the strong dentated 
spine of the pectoral fin of a Siluroid fish, of a new species, and the first that has 
been discovered in a British formation. Fig. 12 is a view of the symmetrical 
dorsal spine of the same Silurus. Fig. 13 gives two views of the articular sur- 
face of the pectoral spine. This rare species is dedicated to Sir P. de M. Grey 
Egerton, Bart., whose unrivalled collection of fossil fishes, and whose intimate 
knowledge of that department of Paleontology, have served on many occasions 
to the advancement of Geology, and have proved of essential aid to the author 
in the present part of his work. 
