1894.] Variation of North American Fishes. 659 
8. Another modification is brought about by the shifting of 
the the lower half of the whole bars backward, which thus be- 
come separated from the dorsal halves. In this, the northern- 
most variety, the nape is naked. 
9. In the simplest pattern, the two sides are usually sym- 
metrical. If unsymmetrical, the asymmetry is introduced in 
the region of the spinous dorsal fin by a shifting forward or 
backward of the bars of one side in this region. 
10. In the more complicated patterns the asymmetry has 
become the rule, and has spread along the region of both 
dorsals. 
11. The variation in the combination of dorsal spines and 
rays is promiscuous. 
12. The variation in the number of dorsal rays is promis- 
cuous. : 
18. The variation in the number of dorsal spines is deter- 
minate. The southern specimens having a larger number of 
spines. Exception: the specimens from San Marcos Spring, 
Texas. 
14. The variation in the number of anal rays is also deter- 
minate. As in the case of the dorsal spines, the number varies 
with the latitude, the southern specimens having a slightly 
larger number of rays. 
EXPLANATION or PLATES. 
Fig. 1. Etheostoma caprodes Rafinesque, 33 mm., Chocola Cr. 
Oxford, Ala. 
Fig. 2. Etheostoma caprodes Rafinesque, 83 mm., Bean Blos- 
som, Ind. : 
Fig.3. Etheostoma caprodes Rafinesque, S8 mm., Chocola Cr., 
Oxford, Ala. 
Fig. 4. Etheostoma caprodes Rafinesque, 102 mm., Green R., 
Greensburg, Ky. 
Fig. 5. Etheostoma caprodes Rafinesque, 115 mm., San Marcos, —— 7 r 
Spr., Tex. 
