PISCES. 213 



cycloid structure. These have recently been placed by Prof. Agassiz in a 

 new family, Percopsidce* 



Galaxid^e. This family, containing but few forms, exhibits characters 

 intermediate between the Sahnonoids and the Esocidce. With a structure 

 somewhat similar to some of the former, it has the dorsal far back, and the 

 intestinal character of the latter. The upper jaw is formed partly by a 

 short intermaxillary, partly by the maxillary. The mouth presents much of 

 the cyprinoid structure. The species are mostly oriental. 



EsociD^. In the Esocidce the body is elongated, the single dorsal placed 

 far back, and opposite the anal. The upper jaw is constituted by the inter- 

 maxillaries, almost entirely ; the maxillaries when they enter as an element 

 are destitute of teeth. Intestines without cceca. Teeth generally well 

 developed in various parts of the large mouth. Branchiostegous rays from 

 three to eighteen. 



The genus Esox is characterized by the broad depressed head and mouth ; 

 the latter with teeth on the tongue, vomer, palatines, and branchial arches. 

 The jaws have long, sharp, compressed teeth. The Esoces, or pikes, are 

 among the most formidable of all fresh-water fish. By reason of their 

 slender elongated form, they are able to live in shallow waters; penetrating, 

 even when of considerable size, into very small bz'ooks. Tyrants of the 

 fresh water, no fish can compete with them except the trout ; and it is very 

 seldom that both forms are found in the same waters. Of two branches of 

 the same stream, one may be peopled by the former, and the other by the 

 latter. The only species of pike found in Europe is the Esox lucius, 

 shown in pi. 82, jig. 3. It is found in all the principal fresh waters of 

 Europe ; where, there is reason to suppose, they are much more abundant 

 at the present time than formerly. This species attains to a weight of 

 70lbs., although individuals of this size are of rare occurrence. North 

 America is especially rich in species of pike : those inhabiting the northern 

 lakes, as the Maskalonge, Esox nobilior, Esox estor, and others, attain a 

 great size. Specimens of the former have been known of over 70lbs. The 

 more southern species, as Esox clathratus, and others, are of more moderate 

 dimensions. The American species may all be referred to two types, one 

 with the opercula entirely scaled, and with fasciated or reticulated darker 

 markings, with a vertical bar under the eye ; the other with the lower half 

 of the operculum free from scales, and the marks in the form of light spots 

 on a dark ground. 



MoRMYRiDiE. This family contains fish characterized by an elongated 

 body provided with oblong scales. The entire head, not excepting the 

 cheeks and operculum, covered by a thick skin completely concealing the 

 bones of the head. This is drawn over the operculum, in such a manner 

 as only to leave a vertical narrow slit in each side : this skin is perforated by 

 a number of pores. Mouth, with the tongue, well armed with teeth. Two 

 coBcal appendages. The fishes of this family are almost all inhabitants of Africa. 



. * Since the above paragraph was written it has been ascertained by Prof. Agassiz that the 

 genus Percopsis, with Corniger (from Brazil) must constitute a distinct order of fishes. It 

 is li-kewise possible that the three species referred to are really one. 



ICONOGRAPHIC ENCYCLOPAEDIA. VOL. II. 27 417 



