I'm not too good with North American species ID, save for the ones native to WA that I learned in Icthyology. But I was curious if there was a good ID sheet and of course fishbase came through for me. Here's a link, http://www.fishbase.org/identification/SpeciesList.php?genus=Etheostoma
They list 156 species, some have pics, others are just descriptions. However, at the top of the page you can fill in some info that will help limit the search. Just tell it if it was fresh or marine and the number of spines in the dorsal fins (total of the two fins) and the number of spines in the anal fin and that will help it narrow it down.