SYSTEMATIC CATALOGUE OF FISHES. 51 



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



divided, the spines V to 11 StromateidjE, in part (butter-fishes). 



kk. Esophagus without dilated sacs containing hooked teeth. 



I. Form oblong or ovate, compressed; qaudal peduncle very slender; 

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

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

 isthmus; preopercle not serrate. 



Caeangid^ (crevalles, pompanbes, etc.). 



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

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

 preopercle serrate PqmatomidjE (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^ (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 HBPATiDiE (surgeon-fishes). 



mm. No spine on side of caudal peduncle. 



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



MuLLiD^ffi; (goat-fishes). 

 nn. Chin without barbels. 



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

 p. Anal spines 3; dorsal fms continuous. 



HjEMTJLID^ (grunts). 

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



SclenidjE (drums). 

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

 q. GUI-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^ (parrot-fishes). 



rr. Teeth more or less distinct and separated. 



IjABRTDjE (lipped-fishes). 

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



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

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

 to isthmus; dorsal fins contmuous. 



ChjBtodontid^ (butterfly-fishes). 

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

 fins either continuous or separate. 

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



absent GobiidjB, in part (gobies). 



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

 u. PremaxiUaries excessively protractile, with long 



basal processes GBEHiDiE (moharras). 



uu. PremaxUlary not protractile or only moderately so. 

 V. Pseudobranchiae absent or undeveloped 



w. Dorsal fin composed of soft rays only, beginning 

 on head; caudal fin very deeply forked; large 



pelagic fishes Cortph^nid.*; (dolphins). 



v)w. 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. 



Centrakchid^. (fresh-water basses). 

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

 Percid^ (perches). 

 w. Pseudobranchiae developed. 



y. MaxiUary not sheathed by the preorb tal, or 

 only partly covered by the latter; no accessory 

 scale in axil of pectoral; accessory ventral scale 

 smaU or wanting; a spine on posterior margin of 

 opercle. 



