Jordan and Ever mann. — Fishes of North America. 1881 



•mm. Lateral line unarmed or with small hidden scales only; hody 

 rather robust; no filumentous spines; top of head scaly; 

 preopercular sjiiue with hut 1 hooked process above. 



ASTROLYTKS, 710. 



kk. Preopercular spine bifid or simple, without hooks or autler-like pro- 

 cesses above. 

 0. Vent very close behind ventrala ; supraorbital cirrus very high. 



Akchistes, 711. 

 00. Vent well behind ventrals; supraorbital cirrus low or wanting. 

 ■p. Back with a distinct band of scales on each side above lateral line ; 

 head smooth above, the interorbital space flat or concave. 

 q. Interorbital space flat; head without cirri above. 



Artedius, 712. 

 qq. Interorbital space concave; top of head witli short cirri. 



AXYRIAS, 71.3. 

 yy. Back covered with rough scales above; head very rough. 



/•. Preopercular spine more or less evidently bifurcate; a small 

 cirrus above eye. Ruscarius, 715. 



rr. Preopercular spine simple; sides scaly below lateral line. 



Eastrinus, 716 

 yyy. Back with a series of larger plates along each side below base of 

 dorsal fin above lateral line ; head naked above ; sides with 

 scattered scales ; body and head slender; skin above with 

 warty scales and prickles. Icelus, 717. 



yyyy. Back and sides wholly naked; preopercular spine simple, 

 strongly hooked upward. Artediellus, 714. 



jj. Vomer with teeth, palatines with none ; the side with a series of bony 

 keeled spinous plates. 

 t. Plates on head larger, similar to those along lateral line ; body very slen- 

 der, depressed above. Eadulinus, 718. 

 tt. Plates on head very small; body rather robust; preopercle with 4 

 spines, the upper hooked upward. Stelgistrum, 719. 

 ii. Last gill arch with a distinct slit behind it. 

 Tt. Sides of body with oblique serrated folds; preopercular spines small, 

 simple or bitid ; gill membranes wholly free from isthmus ; spinous 

 dorsal not emarginate; no palatine teeth; body slender; ventrals 

 moderate. 

 V. Caudal fln truncate or slightly emarginate. 

 w. Back with a series of bony tubercles along l)ase of dorsal; body not 

 very slender, 

 a. Breast naked, with cross folds of skin, containing mucous tubes. 



Triglops, 720. 

 %x. Breast with small scales and no cross folds. Sternias, 721. 



WW. Back without bony tubercles along base of dorsal ; body very .slen- 

 der; lower rays of pectoral produced. Prionistius, 722. 

 vv. Caudal fin deeply forked; body very slender; lower pectoral rays 

 produced. Elanura, 723. 

 MM. Sides of body without oblique, serrated folds ; no bony tubercles along 

 dorsal ; body very robust. 

 y. Back with 1 or 2 bands of large rough scales ; lateral line without bony 

 shields; palatines with teeth ; preopercular spine short. 

 z. Back with one band of scales ; ventrals greatly elongate ; gill mem- 

 branes free from isthmus ; spinous dorsal not notched. 



Melletes, 724. 

 zz. Back and sides with 2 separate bands of coarse rough scales ; ven- 

 trals moderate; spinous dorsal notched, 

 a'. Gill membranes partly free, forming a broad fold across isthmus; 

 naked skin of body firm and thick. KEiiiLEPiuoxus, 725. 



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