14 CONTRIBUTIONS TO NOETH AMERICAN ICHTHYOLOGY II. 



mm. Spinous dorsal low and small, the spines subequal, scarcely half the height 

 of the soft rays, in males ending in little fleshy knobs ; mouth rather 

 large, the lower jaw the longest; body elongated, compressed; lateral 

 line extending less than half the length of the body ; head naked (except 

 in the aberrant E. squamiceps, which is an exception to all these char- 

 acters, save those drawn from the dorsal fin) Etheostoma, 15. 



II. Dorsal fins about equal, well separated ; body elongated ; cheeks and opercles 

 scaly : 



n. Lower jaw longest ; lateral line unknown (genus admitted provisionally, the 

 type-species apparently has not been seen since its original description) : 



Alvarius. 16. 



nn. Jaws about equal ; lateral line curved upward over the pectorals, not 



reaching to middle of body; body elongated Boleichthys, 17. 



fc/v. No lateral line ; dorsal fins small, subequal, well separated ; mouth small, with 

 nearly equal jaws ; scales large ; size smallest of all spiny-rayed fishes, 



MiCKOPERCA, 18. 



CATALOGUE OF SPECIES OF ETHEOSTOMATIDJE. 



The following catalogue includes those species of Etlieostomatidce 

 which appear to be valid, with the geographical distribution of each so 

 far as recorded. Species unknown to me are indicated by a star (*). 

 In arranging the genera, I begin with the type most generalized, or 

 most like ordinary Fercidw, Hadropterus. The relations of the aber- 

 rant genera Pleurolepis and Ammocrypta are probably most with Al- 

 vordius, a fact which cannot well be shown in a linear series. I omit 

 several species, which very likely may prove valid, but of whose rela- 

 tions I can form no definite opinion from the published accounts. lu 

 each genus, the type-species is placed first. 



Hadropterus, Agassiz. 



1. Hadropterus nigrofasciatus, Ag. — South Carolina to Tennessee and 



Louisiana. 



2. Hadropterus tessellatus, Jordan. — Vermont (?) to Pennsylvania. 



3. Hadropterus aurantiacus, (Cope) Jor.*— Yirginia to Tennessee. . 



Ericosma, Jordan. 



4. Ericosma evides, Jordan & Copeland. — Wabash Valley. 



Alvgrdius, Girard. 



5. Alvordius maculatus, (Grd.). — Pennsylvania to North Carolina. 



6. Alvordius aspro. Cope & Jordan. — Upper Mississippi Valley and 



Upper Lake Region. 



7. Alvordius nevisensis, Cope.* — North Carolina. 



