14 CONTRIBUTIONS TO NORTH 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 ZZ. squamiceps, which is an exception to all these char- 
acters, save those drawn from the dorsal fin) ..----..-..- ETHEOSTOMA, 15. 
Ul. Dorsal fins about equal, well separated ; body elongated; cheeks and opercles 
staly: 
n. Lower jaw longest ; lateral line unknown (genus admitted provisionally, the 
type-species apparently has not been seen since its original description) : 
j Atyartivs. 16. 
nn. Jaws about equal; lateral line curved upward over the pectorals, not 
reaching to middle of body ; body elongated .-...----- BOLEICHTHYS, 17. 
kk. No lateral line; dorsal fins small, subequal, well separated ; mouth small, with 
nearly equal jaws; scales large; size smallest of all spiny-rayed fishes, 
MICROPERCA, 18. 
CATALOGUE OF SPECIES OF ETHEOSTOMATID. 
The following catalogue includes those species of Htheostomatide 
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 Percidw, 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. In 
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.*—Virginia to Tennessee. 
ERIcosMA, Jordan. 
4. Ericosma evides, Jordan & Copeland.—Wabash Valley. 
ALVORDIUS, Girard. 
5. Alvordius maculatus, (Grd.).—Pennsylvania to North Carolina. 
6. Alvordius aspro, Cope & Jordan.—Upper Mississippi Valley and 
Upper Lake Region. 
¢. Alvordius nevisensis, Cope.*—North Carolina. 
