Jordan and Evermann.- Fishes of North America. 1883 



qq'. Top of head unarnied,or nearly so; lacustrine species. 



TRIGLOPSIS, 740. 



kkk'. Upper preopcrcular spine stout, armed with 2 or 3 antler- 

 like processes ; slit behind last gill small or wanting ; 

 vonier toothless. GYMNOCANTHUS, 741. 



hh'. First dorsal spine elevated; skin perfectly smooth; gill mem- 

 branes forming a broad fold across isthmus. LEIOCOTTUS, 742. 

 ffg'. Palatine teeth present (rarely obsolete in one species). 



r'. Gill membranes narrowly joined to the isthmus, not forming a 



fold ; preopercular spine with antler-like processes ; skin 



smooth. LEPTOCOTTUS, 743. 



rr'. (Jill membranes free from the isthmus; preopercular spine shorter; 



head and sides usually with many short cirri. 



'. Skin of sides with scattered prickles or rudimentary scales; 

 preopercular spine bifid; head pointed. CLINOCOTTUS, 744. 

 as'. Skin perfectly smooth, without scales or prickles. 

 V . Preopercular spine long and sharp, sometimes with 1 antler- 

 like process above ; snout acute. OLIGOCOTTUS, 745. 

 tV . Preopercular spine sharp, curved, simple; snout acute. 



OXYCOTTUS, 746. 



ttt 1 . Preopercular spine short and blunt ; snout more or less obtuse. 



BLENNICOTTUS, 747. 



, rrr'. Gill membranes free from the isthmus; no cirri; preopercular 



spine slender, hooked upward. [ ARTEDIELLUS, 714.] 



BLEPSIINJE : 

 GC'. Skin almost everywhere rough with small bluntish prickles; first dorsal. 



elevated in front; head small, compressed. 

 u'. Gill membranes free from the isthmus ; ventrals small. 

 v'. Spinous dorsal not emarginate; no smooth areas on body. 



HlSTIOCOTTUS, 748. 



vv'. Spinous dorsal deeply notched ; sides with smooth areas. BLEPSiAS,749. 

 uu'. Gill membranes united to the isthmus ; ventrals long. 



w'. First dorsal little elevated, its base scarcely raised above occiput. 



NAUTISCUS, 750. 



vno'. First dorsal greatly elevated, its base raised abruptly from the 

 depressed occiput. Js r AUTiCHTHYS,751. 



HEMITRIPTERINJE : 



f/fj. Spinous dorsal longer than soft part, of 14 to 18 spines; skin rough, with prickles 

 and tubercles ; teeth on vomer and palatines ; gill membranes free from isthmus ; 

 no slit behind last gill, 



x'. Spinous dorsal of 15 spines, not notched. ULCA, 752. 



xx'. Spiiious dorsal of 16 to 18 spines, deeply notched, the anterior spines highest. 



HEMITRIPTERUS, 753. 

 SYNCHIRIN.JE : 

 l)b. Pectoral fins continuous around the throat. 



y 1 . Back with spinous scales; gill membranes free from isthmus; no slit 

 behind last gill ; teeth on vomer and palatines ; preopercle with a 

 short bifid spine; ventrals inserted far back. SYNCHIRDS, 754. 



ASCELICHTHYIN^ : 



CLCL. Yentral fins wholly wanting. Skin perfectly smooth ; no slit behind fourth gill; 

 gill membranes free from isthmus ; teeth on vomer and palatines. 



ASCELICHTHYS, 755. 

 PSYCHROLUTINJE : 



II. Spinous dorsal not evident, its slender spines wholly hidden in the skin or else indis- 

 tinguishable from soft rays; head unarmed, its hones hidden in lax skin; skin 

 smooth; no slit behind last gill; gill membranes broadly joined to the isthmus; 

 no teeth on vomer or palatines ; maxillary covered by skin of preorbital; ventrals 

 moderate I, 3, the base adnate to body. 



