ETHEOSTOMATID.E. LXXXIX 219 



II. Dorsal fins about equal, well separated ; body elongated ; 



cheeks and opercles scaly. 



7i. Jaws about equal ; lateral line curved upward over the 

 pectorals, not reaching to middle of body ; body elon- 

 gated BOLEICHTHYS, 16. 



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, 17. 



/. AMMOCRYPTA, Jordan. SAND-DIVERS. 



1. A. beanii, Jordan. BEAN'S DARTER. Body very 

 slender; general form and appearance of Pleurolepis; 

 dorsal fins very high; color translucent, with a golden 

 lateral band; dorsal fin with large black spots; D. X 

 10; A. I, 9; lat. 1. 65. Lower Mississippi; a remarkable 

 species. 



2. PLEUROLEPIS, Agassiz. PELLUCID DARTERS. 



1. P. pellucidus, (Baird.) Ag. SAND DARTER. Depth 6 

 to 8 in length; body nearly cylindrical; head elongated, 

 pointed; scales small, finely dotted, far apart, and deeply 

 imbedded; fins small; color pinkish white, pellucid in 

 life, with a series of small, squarish, olive (blue) blotches 

 along back, and another along sides, the spots connected 

 by a gilt line; D. X 9; A. II, 6; length 2 to 3 inches. 

 Ohio Valley, in sandy streams; one of the most interest- 

 ing of our fishes. 



3. PERCINA, Haldeman. LOG PERCHES. 



=Pileoma, DeKay. 



1. P. caprodes, (Raf.) Girard. LOG PERCH. HOG FISH. 

 ROCK FISH. Salmon yellow or greenish, with about 

 fifteen transverse dark bands from back to belly, these 

 usually alternating with shorter and fainter ones reach- 

 ing about to lateral line; a black spot at base of caudal; 

 belly with a row of enlarged plates, shed at some 



