PERCINA— LOG-PERCHES 281 



are less than four inches long, and one of them does not exceed an 

 inch and a half. The name of "darter" is given them because of 

 their quick, swift nights through the water, a fact which also sug- 

 gested to Rafinesque the technical name of one of the early genera 

 described by him— Boleosoma, meaning dart-body. To the fisher- 

 man and the ordinary observer these little percoids are, usually 

 either wholly unknown or go by the general name of minnow, or, 

 perhaps, by the more appropriate one of "perch minnow." They 

 are, as a rule, brilliantly colored, and sexual color-differences are 

 strongly marked in many species, the females being duller than the 

 males. 



The species are much subject to local variation, but they are 

 nevertheless commonly well marked, and the local forms can usually 

 be referred, without much difficulty, to the specific group. All 

 spawn in spring, so far as known. 



Genus PERCINA Haldeman 

 (log-perches) 



Body elongate, subcylindrical; mouth small and inferior; premaxil- 

 laries not protractile ; teeth on vomer and palatines , belly with a median 

 row of enlarged caducous plates; vertebra? (P. caprodes) 44 (23+21); 

 pyloric cteca (P caprodes) 6; pseudobranchiag present, rudimentary. 

 .In the diagnostic features above noted this genus is scarcely different 

 from Hadropterus. On the cranial characters of Percina, which in its 

 skull structure more closely resembles Perca than do the other etheosto- 

 mids, Jordan and Eigenmann have said: "As .compared with the other 

 darters, the skull of Percina is much broader bet-ween the eyes; the parie- 

 tal bones are more strongly ridged, the sutures more distinct, the top of 

 "the cranium beyond the eyes more depressed, and the supraoccipital 

 crest more developed than in most of the others."* The largest of the 

 darters; coloration olivaceous, with dark vertical bands on body, more 

 or less broken into spots and reticulations; species 2. 



PERCINA CAPRODES (Rafinesque) 

 (log-perch) 



Rafinesque, 1818, Amer. Month. Mag., 534 (ScUena). 



J. & G., 499; M. V., 126; B., I, 57; J. & E., 1026; N., 36; J., 39; F., 65; F. F., I. 

 3, 25; L., 26. 



The largest of our darters, length 4 to 6 inches; body cylindrical, 

 elongate ; depth S . 4 to 7 in length ; greatest width of body about f of 



*Proc. U. S. Nat. Mus. Vol. 8, p, 68. 



