ESOCID^E. 123 



ESOCID^:. 



Fish of this family want the adipose fin, and the border of their upper jaw is 

 either formed solely by the intermaxillaries, or if the labials enter at all into its 

 composition, they are destitute of teeth. Their intestinal canal is short, without 

 cseca, most of them have an air-bladder, and, with the exception of the Microstoma 

 of the Mediterranean, all that are known have the dorsal and anal fins opposite to 

 each other. The Esocidce are voracious fish, many of them inhabitants of rivers. 

 Most of the family is comprised in the Linnean genus Esox, which is subdivided 

 in the Regne Animal into ten sub-genera, that differ from each other by many 

 striking characters, such as the form of the body, which varies from a tolerably thick 

 shape to a very slender one : the size of the scales, which may be moderately large, 

 or quite imperceptible, or there may be a series of strong scales on the lateral line, 

 or a row of keeled ones on each side of the belly : the mandibles also vary greatly 

 in form, and somewhat in composition ; thus both jaws may be moderately long 

 and of equal length, or the upper one may be very short and the under one either 

 simply projecting beyond it, or having its symphysis lengthened out into a half 

 beak, or both jaws may be prolonged in the shape of a slender bill ; the labials 

 may form almost the half of the upper border of the mouth, or they may be alto- 

 gether posterior to it, or even fixed to the cheek : there is an equal variety in the 

 dentition, the teeth being, in some cases, small and confined to the margins of the 

 jaws, in others long, card-like, and densely crowded on the mandibles, vomer, 

 palate-bones, base of the tongue, branchial arches, and pharyngeal bones, or the 

 pharyngeal teeth may be en pave : the gill-covers have also very different forms in 

 the different sub-genera, and in one case they are reduced to little membranous 

 flaps : the gill-rays vary in number from three to eighteen or more. The stomias 

 barbatus differs from the rest of the genus Esox in having a very long barbel on 

 the lower jaw. 



The following species, among others, belong to the seas or fresh waters of the 

 United States. Esox estor, reticulatus, niger, phaleratus, and lucius, Belone 

 truncata, Scomber-esox scutellatas, and perhaps equirostrum, Exoccetus ecciliens, 

 E. furcatus, Mitch, (or E. Nuttallii, Le Sueur, /. c., f. 1), and E. comatus, 

 Mitch, (or E. appendiculatus , Wood, Journ. Ac. Sc. Phil., iv., p. 278). Several 

 species of Belone, Hemiramphus, and Exoccetus frequent the Caribbean Sea. The 



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