SYSTEMATIC CATALOGUE OP FISHES. 51 



k. Esophagus with dilated sacs containing hooked teeth; dorsal fins 



divided, the spines 7 to 11 Stromateid^, in part (butter-fishes). 



kk. Esophagus without dilated sacs containing hooked teeth. 

 /. Form oblong or ovate, compressed; caudal peduncle very slender; 

 anal fin preceded by 2 free spines; posterior part of lateral line 

 with or without a series of keeled plates; gill-membranes free from 

 isthmus; preopercle not serrate. 



Carangid.e (crevalles, pompanoes, etc.). 



//. Form compressed, anal fin preceded by 2 obsolete spines; lateral 



line without keeled plates; gill-membranes not attached to isthmus; 



preopercle serrate Pomatomid.e (blue-fishes). 



III. Form very deep and compressed; caudal peduncle wide: anal spines 

 connected with remainder of fin; no series of keeled plates on lateral 

 line; gill-membranes broadly joined to isthmus; preopercle not serrate. 



Ephippid.e (spade-fishes). 

 nil. Form compressed, shape various; no free anal spines; no series 

 of keeled plates on lateral line. 



m. A concealed, erectile, lancet-like spine on each of caudal peduncle; 

 gill-membranes united to isthmus; preopercle not serrate; body 



ovate Hepatid^ (surgeon-fishes). 



m?ra. No spine on side of caudal peduncle. 



n. Chin with 2 long barbels; 2 dorsal fins well separated. 



MuLLiD^ (goat-fishes). 

 nn. Chin without barbels. 



0. Lateral line extending to posterior margin of caudal fin. 

 p. Anal spines 3; dorsal fins continuous. 



H^MULiD^ (grunts). 

 pp. Anal spines 1 or 2; dorsal fins distinct. 



ScLENiD^ (drums). 

 00. Lateral line extending only to base of caudal fin. 

 q. Gill-arches 3.5, a small cleft or no cleft behind last 



r. Teeth on each side, of each jaw united, forming a kind 



of beak Scarid.e (parrot-fishes). 



rr. Teeth more or less distinct and separated. 



Labrid^ (lipped-fishes). 

 qq. Gill-arches 4, a long cleft behind last. 



s. Teeth setiform: body very deep, nearly as deep as long; 

 soft fins scaly; lateral line present; gill-membranes united 

 to isthmus; dorsal fins continuous. 



CH^TODONTiDiE (butterfly-fishes\ 

 ss. Teeth not setiform; body much longer than deep; dorsal 

 fins either continuous or separate. 

 t. Gill-membranes broadly united to isthmus; lateral line 



absent Gobiid^, in part (gobies). 



It. Gill-membranes free from isthmus ; lateral line present. 

 u. Premaxillaries excessively protractile, with long 



basal processes Gerrid^e (moharras). 



uu. Premaxillary not protractile or only moderately so. 

 V. Pseudobranchise absent or undeveloped 



w. Dorsal fin composed of soft rays only, beginning 

 on head; caudal fin very deeply forked; large 



pelagic fishes. Corypilenid^ (dolphins). 



WW. Dorsal fin with strong spinous rays anteriorly, 

 not beginning on head; caudal fin not very 

 deeply if at all forked; fresh-water fishes. 

 X. Anal spines 3 to 10; dorsal spines 4 to 13. 



Centrarchid.e. (fresh-water basses). 

 XX. Anal spines 1 or 2; dorsal spines 6 to 15. 

 Percid.e (perches). 

 w. Pseudobranchise developed. 



y. Maxillary not sheathed by the preorb tal, or 

 only partly covered by the latter; no accessory 

 scale in axil of pectoral; accessory ventral scale 

 small or wanting; a spine on posterior margin of 

 opercle. 



