class pisces. 397 



The seas of America produce some with barbels, 

 sometimes simple \ sometimes double, and even 

 branched 2 . 



We place at the end of the family of the Esoces, a 

 genus which differs little from them, but which has 

 the intestines longer, and two cceca. It will very 

 probably give occasion to form a particular family. 

 It is that of 



Mormyrus, L. 3 



These are fishes with compressed, oblong, scaly 

 body ; tail, slender at the base and enlarged towards 

 the fin ; the head is covered with a naked and thick 

 skin, which envelopes the opercula and the rays of 

 the gills, and leaves for their aperture only a vertical 

 cleft, which has caused some naturalists to deny their 

 opercula, though they have them as complete as any 

 fish ; and to reduce to a single one their branchial 

 rays, although they have five or six. The aperture 



much. It is not easy to distinguish them in the relations and the 

 figures given by travellers. The evolans of Linnaeus appears to be 

 only a volitans whose scales had fallen. 



1 Exocetus comatus, Mitch. Trans. New York, I. pi. v. f. 1., pro- 

 bably the same as the Ex. ajjpendiculatus, Will. Wood, Ac. Sc. 

 Nat. Philad. IV. xvii. 2. 



2 Exocetus jurcatus, Mitch, op. cit. f. 2, which I suspect to be the 

 same as the Ex. Nutlalii, Lesueur, Sc. Nat. Phil. II. iv. 1. 



3 Moppvpog, the Greek name of a fish of the littoral sea, and 

 varying in colour ; probably the Sjmrus mormyrus, L. It has been 

 applied erroneously enough by Linnaeus to fishes of the fresh water, 

 and of an uniform colour. 



