§ 40. FISHES OF THE SUSSEX CHALK. 359 



From the resemblance of the teeth of this fish to those of reptiles, it 

 was supposed that the original belonged to an extinct genus of 

 saurians ; but in 1833, a considerable portion of the head, with the 

 maxillae, many vertebrae, &c, were discovered in a block of chalk, 

 near Lewes, and the true characters of this remarkable ichthyolite 

 determined. 



The statement that the teeth of the Saurodon and Saurocephalus 

 were first ascertained to belong to fishes, and not to reptiles, by the 

 microscopical observations of Prof. Owen, is not correct, for M. Agassiz 

 had long previously determined their true characters. 



*#* The following fishes have been named by Iff. Agassiz, since the 

 above table was constructed. 



Acrogxathus hoops. Lign, 72, page 347. Natural size. Agass. Poiss. Foss. Vol. 

 iii. tab. 60 a , figs. 1,4. An unique specimen from Southerhani 

 quarry, near Lewes. 



Aulolepis typus. Lign. 73, page 348. Length 6 inches. An unique specimen, 

 from Clayton chalk-pit, Sussex. One nearly perfect example has 

 alone been found. Poiss. Foss. Vol. iii. tab. 60, figs. 5, 8. 



Belonostomus ductus. Agass. Poiss. Foss. Vol. ii. tab. 66a, figs. 10 to 13. 



Chimera Agassizii. Agass. Poiss. Foss. Vol. iii. pi. 40, figs. 3, 5. (Determined 

 by Dr. Buckland.) The beaks or mandibles have alone been dis- 

 covered. 



Mantelli. Lign. 71, page 343. Agass. Poiss. Foss. Vol. iii. PI. 40, figs. 



1, 2. Two mandibles were found, many years since, in a block of 

 chalk, near Lewes. This species also occurs in theShanklin sand 

 of Kent. A beak has been found by Mr. W H. Bensted, in the 

 Iguanodon quarry, near Maidstone. 



Tetrapterus minor. Lewes. Agass. Poiss. Foss. Vol. iii. tab. 60, figs. i. 4. 



Caturus similis. Agass. Poiss. Foss. Vol. ii. tab. 66a, fig. 9. 



AcROTEMNUs/a&a. Poiss. Foss. Vol. ii. tab. 66a, figs. 16, 18. 



