PERCOIDE.E. 19 



lowing remark upon it. " Cychla cenea de Le Sueur, Centrarchus aneus, Nob.'" 

 Since that period, however, the seventh volume of the Histoire des Poissons has 

 appeared, wherein the genus Centrarchus is revised by M. Valenciennes, and some 

 changes made in the specific names, in consequence of many more specimens 

 having been sent to him from various parts of the United States. In the third 

 volume it is said, " Les centrarchus ont le corps ovale, comprime, un dorsale unique, 

 des dents en velours au machoires, au-devant du vomer, aux palatins et sur les 

 bases de la langue ; le preopercule entier ; Tangle de Vopercule divise en deux 

 pointes plates. Nous les avons nommes centrarchus ou anus epineux, a cause die 

 nombre assez considerable des epines de leur anale, qui va a cinq ou six, tandis que 

 dans la plupart des genres voisins il nest que de trois." In the seventh volume 

 this character is modified as follows : — " Nous avons vu deux especes de centrar- 

 chus qui n'ont que trois epines a Panalc, comme cest V ordinaire cliez le plus grand 

 nombre des acanthopterygiens ; mats ce genre nest pas moins facile cependant a 

 reconnoitre par V absence de dentelures au preopercule et surtout parce que des 

 dents en velours ras existent sur les palatins, le vomer et la base de la langue." 

 (p. 456.) Bryttus is distinguished from the preceding genus solely by the want of 

 teeth on the tongue ; and Pomotis is known from both by the tongue and palate being- 

 smooth, the preoperculum slightly toothed, and the operculum ending in a rounded, 

 membranous ear-like lobe. Some of these characters*, so far from being of generic 

 importance, will scarcely serve to distinguish species ; and it will be seen, by the 

 description given below, that our specimen of Centrarchus aneus has the preoper- 

 culum distinctly serrated or denticulated. It appears, therefore, to us, that it 

 would be more convenient and better to re-unite the three genera into one, which 

 will stand in the division of Thoracic Percoidese having five soft rays in the 

 pectorals ; fewer than seven branchiostegous rays ; only one dorsal ; and no canine 

 teeth. 



On comparing our Lake Huron specimen of Centrarchus ceneus with the 

 description of the species in the Histoire des Poissons, the only discrepancies are, 

 that there the anal is said to commence opposite to the sixth dorsal spine, while in 

 Le Sueur's original figure, as well as in our specimen, it begins opposite to the 

 tenth ; no notice is taken by the Baron of the singular oval plate of teeth on the 

 centre of each palate-bone, and he says, " cest a peine si Von pent dire qiiil y a 

 une dentelure au preopercule" The edge of the preoperculum, in our specimen, 



* Even the character of teeth on the palate is of little importance as a generic distinction in some families of fish. See 

 Thymallus sigmfer, which resembles the Common Grayling very closely in its general form, but differs from it in having 

 palatine teeth. 



d2 



