66 PROCEEDINGS OE THE ACADEMY OF 



backwards. The anal fin is longer than deep, convex upon its edge ; its an- 

 terior margin being placed somewhat behind a vertical line drawn at the an- 

 terior margin of the second dorsal, but the same line intersects the vent. The 

 caudal fin, which is a little shorter than the head, is truncated upon its pos- 

 terior margin. The ventrals are of moderate development compared to the 

 other fin, their middle rays being the longest ; these fins assume a spear- 

 shaped appearance in the state of rest. Their extremities are far from reach- 

 ing the vent. The pectorals, much larger than the ventrals, assume the same 

 shape as the ventrals, under similar circumstances, but when expanded, their 

 posterior margin is quite convex. Their extremities project beyond those of 

 the ventrals, although they do not reach a vertical line intersecting the vent. 

 The rays of the fins are : B ix ; 15+1 ; A 11 ; C 10, 1, 7, 7, 1, 9 ; V 1, 5 ; P 

 13. The scales are of moderate size, deeper than long, anteriorly truncated 

 and posteriorly rounded, exhibiting radiating furrows upon their anterior sec- 

 tion, and numerous, slender, needle-like pectinations upon their posterior 

 margin. The lateral line constitutes the seventh series of scales, counted from 

 the second dorsal fin. 



The ground color is yellowish brown, the dorsal region being maculated with 

 blackish brown, whilst the ventral region is unicolor. A series of large 

 blotches may be observed along the dorsal line affecting both sides of the back, 

 and a series of smaller blotches along the lateral line. There is also a black 

 streak on either side of the snout, and a vertical one beneath the eye. The 

 caudal and pectorals are transversally barred with black, the dorsals irregu- 

 larly vermiculated, giving these fins a checkered appearance. The first dorsal 

 is moreover provided with a jet black spot upon its anterior edge, between the 

 first and second rays. The anal and ventrals are blackish, the tint being 

 lighter at the base of these fins than towards their periphery. 



The black spot at the anterior margin of the first dorsal fin, has suggested 

 the specific name of E. atromaculata, by which we propose to designate this 

 fish. 



XVIII. A third, and much larger species of Etheostomid occurs in the waters 

 of the Potomac river. It is identical with the one from the Susquehanna river, 

 described by Prof. Haldeman under the name of Percina nebulosa. * 



XIX. Etheostoma caprodes of Rafinesque, is very closely allied to Percina 

 vebulosa, so closely, indeed, that we are not yet prepared to point out the dif- 

 ferences with a sufficient degree of accuracy. But whatever it may be Etheos- 

 toma caprodes must be referred to the genus Percina of Haldeman, as having 

 priority over that of Pileoma of BeKay. Both of these genera were published 

 in 1842, but since Percina is quoted by BeKay, | it evidently shows that it was 

 issued from the press before Pileoma. That the genus Percina, as first con- 

 stituted, contained heterogeneous species, is no ground for rejecting it alto- 

 gether, and the species first enumerated must be considered as its type. 



XX. Hence, should Pileoma semifasciatam prove specifically distinct from 

 Percina nebvlosa, it will be the third species of the genus Percina under the 

 name of Percina semifasciata. 



XXI. The Etheostomid from Lake Superior, described as Pileoma zebra, is to 

 be a fourth species of Percina under the appellation of Percina zebra. 



XXII. Finally a fifth species of the genus Percina was described by us in the 

 " Ichthyology of the U. S. and Mexican Boundary Survey," under the name 



* Journ. of the Acad, of Nat. Sci. Philada. viii. 1842, 330. 

 fNew York Fauna, Part iv. 1842, 162. 



[Feb. 



