450 ORDER MALACOrTERYGII ABDOMINALES. 



the sides by the maxillaries. An osseous piece 

 chagreened like those of the rest of the head, covers 

 the entire cheek : they have only a flat ray at the gills ; 

 their elongated body is invested with stony scales, as 

 in lepisosteus, and, what at the first glance distin- 

 guishes them from all other fishes, is, that they have 

 along the back a great number of separate fins, each 

 supported by a strong spine, which has some soft rays 

 attached to its posterior face. The caudal surrounds 

 the end of the tail, and the anal is very near it ; the 

 ventrals are very far back ; the pectorals are sup- 

 ported on a scaly arm a little elongated. Around each 

 jaw is a rank of conical teeth, and behind some teeth, 

 close and even, or rasp-like. Their stomach is very 

 large, their canal narrow and straight, with a spiral 

 valvule and a single coecum ; their natatory bladder 

 double, with large lobes, particularly that on the left 

 side, communicates by means of a large hole with the 

 oesophagus. 



There is one species of this fish with sixteen dor- 

 sals, discovered in the Nile by M. Geoffroy, Polypterus 

 bichir, Geoffr. Ann. Mus. I. v. ; and another from 

 Senegal, which has but twelve dorsals on the back, 

 P. Senegalus, Cuv. Their flesh is good eating. 



