Ixii FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



11. Anal spines single; dorsal spines slender, PAGE 



3 to 8 ..." Atherinidce 165 



bb. Ventral fins present, thoracic or jugular, 

 m. Ventral fins each composed definitely of 

 one spine and 5 soft rays; eyes symmet- 

 rical, one on each side of the head, 

 n. Ventral fins completely united; gill mem- 

 branes joined to the isthmus; no lateral 



line Gobiidcs 225 



nn. Ventral fins separate. 

 o. Nostril single on each side; lateral line in- 

 terrupted; anal spines 3 to n Cichlidce 204 



oo. Nostril double on each side; lateral line 



not interrupted. 



p. Lateral line extending on caudal fin. 

 q. Anal spines 3, the second very strong, 

 r. Porsal fins two, separate; preopercle 

 with two margins, the posterior one 



strongly toothed Centropomida 198 



rr. Dorsal fins connected; preopercle with 



one margin Hcemulidce 199 



qq. Anal spines i or 2 Scicenida 202 



pp. Lateral line, if present, not extending on 



caudal fin. 



s. Dorsal fins separate or scarcely con- 

 nected, 

 t. Anal spines 3; the second very strong; 



body elongate, compressed Hamulida 199 



tt. Anal spines i or 2 ; body usually slender, 



never much compressed, 

 u. No lateral line; ventral fins with the 

 inner rays the longest; dorsal spines 



8 or less Gobiidce 225 



uu. Lateral line present ; ventral fins with 

 the outer rays the longest; dorsal 



spines 8 or more Percida 196 



ss. Dorsal fin single, the spinous and soft 

 portions being connected; body usually 

 deep and much compressed, 

 mm. Ventral fins each not composed definitely 

 of one spine and 5 soft rays; eyes unsym- 

 metrical, both being on the same side of the 

 head Soleida 234 



