2a. (From 1b.) Lateral stripe narrow, no wider than 2 scale rows anteriorly; scales below lateral band and forward of pelvic fins not outlined with pigment; circumpeduncular scale rows usually 13 to 16.
stargazing minnow
Phenacobius uranops
 

2b. (From 1b.) Lateral stripe 2 1/2 to 4 scale rows wide anteriorly; scales below lateral band and forward of pelvic fins outlined with narrow band of pigment; circumpeduncular scale rows usually 15 to 19.
riffle minnow
Phenacobius catostomus