EGERTON ON PONDICHERRY FISHES. 167 



ing distinctive characters. The surface of the enamel is more 

 smooth and even, in consequence of the fineness of the longitudinal 

 striae, which in E. lialocyon are coarse and strongly marked. The 

 transverse bands are broader, and the form of the teeth is less 

 attenuated. The most important feature it presents is in the finely 

 serrate cutting edge, which in all the specimens I have seen of 

 E. halocyon is smooth and entire. A second fragment corresponds 

 in all these points. The third specimen is a smaller tooth, and 

 only differs from E. halocyon in the smooth and highly polished 

 surface of the enamel. None of these teeth are perfect. The 

 length of the largest is half an inch, of the smallest two lines. 



Ganoid Order. 

 Pycnodont Family. 



Speuerodus rugulosus Eg. — All the tritoral teeth in the Indian 

 collections appear to belong to one species of the 

 genus Sphaerodus. A pretty group in Mr. Kaye's SSSn O 



series shows nine teeth in situ of those in use, and 

 underneath there are the germs of several of their 

 successors. Three detached teeth appear to have belonged to the 

 same specimen. In Mr. Cunliffe's collection I have found two 

 tritores, considerably larger than the specimens alluded to above, 

 but evidently belonging to the same species. In size these teeth 

 resemble those of Sphcerodus Lens, the smallest species figured by 

 Agassiz ; in regularity of form they approach nearer to Sphcerodus 

 parvus ; but they are distinguished from these species and all others 

 figured by Agassiz by the wrinkled or shrivelled appearance of the 

 superficies of the teeth. This is visible even in the smallest speci- 

 mens, and forms a well-marked and easily appreciable specific 

 character. 



Placoid Order. 



Squaloid Family. 



Corax pristodontus Agass. Poiss. Foss. vol. iii. p. 224. — A 

 single fragment is the only evidence upon which rests 

 the supposition that this species enjoyed the extended 

 geographical range indicated by its occurrence in the 

 Cretaceous system of Europe and India. This speci- 

 men shows the outer surface of the hinder portion of 

 a sinistral tooth. The base is wanting. It corre- 

 sponds in minutest detail with the analogous portions of a tooth 

 received from Professor Goldfuss, named by Agassiz Galeus (now 

 Corax) pristodontus, apparently from the Maestricht beds. A 

 comparison with the figures given in the " Poissons Fossiles " yields 

 a like result. Some specimens in Mr. Lyell's cabinet, from the 



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