1882 Bulletin //, United States National Museum. 



aa'. Gill membranes united, not forming a distinct fold across isthmus 

 (unless the skin is shrivelled) ; naked skin thin and lax. 



Caltcilepidotus, 726. 

 yy. Body without scales, hut with a band of coarse bony plates along 

 lateral line ; gill membranes broadly united to the isthmus. 

 6'. Preopercular spine simple, very long and strong. Enophrys, 727. 

 bh'. Preopercular spine extremely long, armed above with recurred 

 hooks. . CERATOCorTCs, 728. 



hk. Body not definitely scaly above, the skin smooth, prickly, villous, or with scat- 

 tered scaly processes; no bony armature to lateral line. 



COTTIN^ : 



c'. Skin smooth or warty or velvety, not evenly hispid with stiff prickles. 

 e'. Gill membranes broadly united to the isthmus, not forming a fold 

 across it; fresh-water species with the head feebly armed; pala- 

 tine teeth present or absent. 

 /'. Ventrals with a concealed spine and 4 soft rays; skin often prickly. 



COTTUS, 729. 

 /J'. Yentrals with a concealed spine and 3 soft rays ; skin not prickly ; 

 palatine teeth usually obsolete. Ueanidea, 730. 



ee'. Gill openings narrowly joined to the isthmus, without fold. 



[Leptocottus, 743.] 

 eee'. Gill membranes free from the isthmus or else forming a broad fold 

 across it. 

 (/'. Palatine teeth none. 

 h'. First dorsal spine not especially elevated. 

 i'. Preopercle with 3 spines only, the upper straight, the third 

 turned downward: skeleton well ossified; lateral line devel- 

 oped, with or without concealed plates. 

 j'. Lower jaw shorter than tipper; suprascapula with a single 

 spine. Myoxocephalus, 731. 



jj'. Lower jaw longer than upper; suprascapula with a double 

 spine, the upper branch shorter. Megalocottus, 732. 



ii'. Preopercle with 4 spines, the lowermost or fourth turned down- 

 ward; bones of head more or less cavernous; lateral line 

 often modified or reduced to scattered pores. 

 k'. Upper preopercular spine curved or hooked upward or else 

 obsolete and hidden in the skin ; skin smooth ; occipital 

 ridges little developed. 

 l. Nasal spines obsolete : bones of head soft and spongy ; lower 

 jaw projecting; lateral line reduced to scattered pores; 

 deep water sculpins allied to Psych rohtteg. 

 m'. Vomer with teeth ; palatines with none. 

 n'. Preopercular spines distinct, uppermost long, sharp. 

 o'. Dorsals well separated Zesticelus, 733. 



00'. Dorsals contiguous. Dasycottcs, 734. 



nn'. Preopercular spines very short, bidden in the skin; 

 dorsal tin continuous. Cottunculus, 735. 



mm'. Vomer and palatines toothless. Malacocottus,"736. 

 W. Xasal spines strong ; bones of head firm ; lower jaw included. 

 p'. Ventral fins very long, reaching past front of anal. 



AKGYEOCOTTU'S, 737. 

 pp'. Ventral fins moderate, not reaching vent. 



POBOCOTTUS, 738. 

 kk'. Upper preopercular spine straight; lateral line chain-like: 

 vomer with teeth, an evident .slit behind last gill. 

 q'. Top of head with ridges or crests ; marine species. 



Oncocottus, 739. 



