20 NORTHERN ZOOLOGY. 



has been cleared by insects, and the serratures are very evident; while the descrip- 

 tion in the Histoire des Poissons was taken, most probably, from fish preserved in 

 spirits, and, consequently , with the soft parts entire. Le Sueur also describes the 

 gill-covers as without spines or denticulations. The Baron states the scales to be 

 " striees en event ail, a huit crenelures ;" whereas we observe fourteen or more 

 crenatures. M. Le Sueur's figure represents a more elongated fish than our 

 specimen. I have been particular in noting these minute and apparently trivial 

 differences, because of the following passage in the Histoire des Poissons, which 

 requires that the species of the individual we have to describe should be deter- 

 mined with the greatest possible precision. 



" Le centrarchus que nous designions sous le nom de sparo'ide (t. iii., p. 88, et 

 pi. 48,) c'est trouve parmi les poissons recueillis dans Vexpcdition si hardie du 

 Capitaine Franklin. II avait etc peche dans le lac Huron : les naturels le donnerent 

 au Docteur Richardson sous le nom anglais de ' rock basse.' Notts avons reconnu 

 que cette espece nest pas le veritable lahre sparo'ide de M. de Lacepede ; ainsi 

 nous V appellerons le centrarchus a six epines (centrarchus hexacanthus, JVob.), et 

 nous reporterons le nom de sparo'ide a I espece qui nous est recemment parvenu et 

 qui a, comme le dessin original de M. Bosc Vindique, neuf epines a 1'anale." A 

 mistake has here occurred as to the origin of the specimen now called C. hexacan- 

 thus, which was not procured by us, but was very likely sent by M. Le Sueur 

 from the Wabash (see Hist, des Poiss., t, iii., p. 88). The only one we saw is 

 the one described at length below, and which, as I have mentioned above, was 

 labelled C. ceneus by the Baron himself : it was then returned to us, and could 

 not have been examined by M. Valenciennes in his revision of the genus. C. hex- 

 acanthus is readily distinguished, not only by having but six dorsal spines, but 

 also by the great length of the soft portion of the anal, and many other particulars 

 which will at once appear on comparing our figure with t. xlviii. in the Hist, des 

 Poiss. M. Le Sueur s original name of nigro-maculatus might have been retained 

 instead of the new one of hexacanthus, had it not been applicable to most species 

 of the genus. 



DESCRIPTION 

 Of a dried specimen from Lake Huron. 



Form. — Body short and much compressed : its profile oval, the hack, however, more arched 

 than the belly, with a short strap-shaped tail issuing immediately behind the dorsal and anal 

 fins ; the profile descends in a rapid curve from the dorsal to the snout, with a slight gib- 

 bosity between the orbits. The length, excluding the caudal fin, is a little more than twice 

 the height of the body at the fore part of the dorsal, where it is greatest. 



