218 FISHES. 



h. No teeth on vomer or palatines ; mouth small, contracted, 

 subinferior ; head short and thick, with swollen cheeks ; 

 spinous dorsal rather long; maxillary non-protractile; 

 anal spines strong; body elongated, little compressed. 



DIPLESIUM, 9. 



hh. Vomerine teeth present ; dorsals contiguous, but distinct ; 

 the spinous dorsal short ; max. protractile; the mouth 

 rather small, horizontal, subinferior. 

 i. Anal spines two, well developed ; the first the longer. 



ULOCENTRA, 10. 

 ii. Anal spines obscure and undifferentiated from the soft 



rays BOLEOSOMA, 11. 



gg. Upper jaw not protractile. 



j. Gill membranes broadly connected across breast ; 

 scales large ; cheeks and opercles scaly ; mouth small, 

 horizontal, subinferior (as in Boleosoma); caudal pe- 

 duncle rather slender. . . . NAHOSTOMA, 12. 

 j}. Gill membranes nearly free ; body rather short, 

 deep, strongly compressed ; scales small ; cheeks naked ; 

 mouth rather large, oblique (as in P&cilichthys) ; caudal 



peduncle deep NOTHONOTUS, 13. 



"** Lateral line incomplete or wanting ; no ventral plates ; upper 

 jaw not protractile; second dorsal larger than anal; vomer 

 with teeth. 

 k. Lateral line present on anterior part of body; anal spines 



two. 



I. Lateral line nearly straight 



m. Spinous dorsal fin well developed, two-thirds or more 

 the height of the second ; the spines graduated, never 

 ending in little fleshy knobs ; lateral line extending 

 more than half the length of the body ; mouth moder. 

 ate, the upper jaw usually a little the longer; gill 

 membranes free. . . . PfEcrLiCHTHYS, 14. 

 man. Spinous dorsal low and small, the spines subequal, 

 scarcely half the height of the soft rays, in males end- 

 ing in little fleshy knobs ; gill membranes connected ; 

 body elongated, compressed. . ETHEOSTOMA, 15. 



