UPPER, OR FLINTY CHALK. 237 



Figs. 1, and 3, are said by Mr. Konig, to resemble those of the Jew 

 fish. Scales of this kind are figured by Knorr, in his Monumens des Ca- 

 tastrophes, but I have no opportunity of referring to that celebrated work. 



Fig. 2, a scale with its process of attachment. 



Fig. 5, lozenge-shaped scales, their recent analogue unknown. 



Localities. Upper, and Lower chalk, near Lewes. 



116. Esox Lewesiensis. Tab, xli. figs. 1, 2. Tab, xxv. fig. 13. Tab. 

 xxxiii. figs. 2, 3, 4. 



The specimen represented in Tab. xH. fig. l, is one of the most re- 

 markable fossils of the Sussex chalk. It is evidently the lower jaw of a 

 fish, whose recent prototype is unknown. The dentature of the maxilla in 

 certain species of Esox or Pike, is very analogous, and in all probabihty, the 

 interesting relic before us, will hereafter be found to belong to an extinct 

 or unknown species of that genus. The engraving conveys so accurate an 

 idea of the original, that a brief description will suffice. 



The jaw is nearly perfect, and is attached to the chalk by the left side, 

 the opposite portion lying in alto relievo. Notwithstanding the brittle 

 nature of the specimen, the chalk has been removed from the interior, and 

 the dentature on both sides is completely exposed*. The maxilla, in- 

 cluding the articulating process, is nearly six inches long, but the den- 

 tated part does not exceed 3-5 inches. It is about one inch wide at the 

 posterior part, and gradually contracts towards the front, which is only 0-5 

 inch wide. 



There are twelve teeth remaining, viz. seven on the left side, and 

 five on the right ; these are not fixed in sockets, but united to the jaw 

 by anchylosis. They have a glossy surface, and are exceedingly brittle ; 

 differing most essentially in this respect from those of the shark, and other 

 fishes previously noticed. The two anterior teeth are nearly an inch in 

 length, and possess a very peculiar form ; they are broad at the base, and 

 suddenly contracting, terminate in a point ; they are convex behind, and 



* To the young collector it may not be unimportant to learn, that in clearing specimens 

 of this kind, it is necessary to leave small brackets of chalk to support the teeth ; without this 

 precaution, the brittle nature of the latter is an insurmountable obstacle to their preservation. 



