FAMILY XIV. ATHERINIDJE. 165 



forms a more or less distinct sheath; PAGE 



ventral with an accessory scale; lateral 

 line usually extending on the caudal fin. 

 h. Anal spines 3, the second long and very 



strong. , 



i. Vomer and palatines with teeth; pre- 

 opercle with 2 margins, the posterior 



one strongly toothed Centropomida 198 



ii. Vomer and palatines without teeth; pre- 



opercle with single margin Hcemulida 199 



hh. Anal spines 2 ; lateral line extending on 



the caudal fin Scianidce 202 



ee. Lateral line interrupted, usually ceasing 

 opposite the posterior part of the dorsal, 

 and then recommencing lower down on 

 the caudal peduncle; anal fin with 3 or 

 more spines; dorsal fin single, the spinous 

 portion usually longer than the soft por- 

 tion. Cichlidce 204 



bb. No lateral line; ventral fins close together, 

 separate, or fully united, the inner rays the 



longer Gobiida 225 



aa. Eyes unsymmetrical, both on same side of the 

 head ; fins without spines ; dorsal fin very long, 

 of more than 40 rays Soleida 234 



Family XIV. Atheriiiidse. 



Body elongate, somewhat compressed, covered with scales of 

 moderate or small size, and usually cycloid; no lateral lines; some 

 scales often with rudimentary mucus tubes; mouth moderate, ter- 

 minal; premaxillary usually protractile; opercle without spines or 

 serrations; gill openings wide, the membranes not connected; free 

 from the isthmus; gills 4, a slit behind the fourth; pseudobranchiae 

 present; dorsal fins 2, well separated, the first of 3 to 8 slender flexible 

 spines, the second of soft rays; ventral fins small, abdominal, of one 

 spine and 5 soft rays: pectorals inserted high; air bladder present; 

 no pyloric cceca. 



KEY TO THE GENERA OF ATHERINID^E. 



a. Belly before ventrals not compressed to an 

 edge ; pectoral fin equal to or shorter than the 

 head. 



