298 JL. Agassiz on Fishes of the Tennessee River. 
them, &c. There are hesides marked differences between the 
young and the adults. These circumstances render it impossible 
to characterize any one species without comparative descriptions 
and figures. The species from Huntsville, known there under 
the name of Trout, differs equally from the northern species men- 
tioned in my “Lake Superior,” and from that of the Southern 
States described by Cuvier and Valenciennes as Grystes salno- 
neus. Its snout is shorter, the posterior end of the upper maxillary 
extends beyond the hinder border of the eye, the head is higher, 
aud the scales much larger in the dorsal as well as in the ventral 
regions. No teeth on the tongue. I call this species provision- 
ally Girystes nobilis, Ag. It reaches a large size, and weighs. 
occasionally from ten to fourteen pounds. : 
2. Cenrrarcuus, Cuv.—Under this name Cuvier has combined 
a variety of Percoids agreeing in general form; their body being 
oval aid compressed, and the two dorsals continuous; but these 
fishes differ from one another in so many respects that they 
require to be further subdivided.* I shall retain the name of 
Centrarchus for that group of species of which Centrarchus 
irideus may be considered as the type. Thus circumscribed, the 
genus Centrarchus may be characterized .as follows: Body very 
broad, greatly compressed, above as well as below. Dorsal long 
spinous and soft rays ; spinous portion of the fin largest. Ana 
shaped like the dorsal, but with fewer spinous rays, extending 
between the ventrals. Mouth small. No species of this geuus 
has been found in the Tennessee River. 
3. Pomoxis, Rafin.—Vhis genus was established by Rafinesque 
for a species closely allied to the Centrarchus hexacanihus of 
Cuv. and Val., and it well deserves to be retained. ‘The boay '8 
much elevated and compressed, resembling somewhat Central- 
chus proper. Like that genus it has a high dorsal and a high anal, 
of nearly equal size, and the spinous portion of these fins rises 
towards the soft rays without a depression ; but in Pomox!s the 
soft portion of these fins is much the largest, whilst it 1s the 
smaller in Centrarchus ; in Pomoxis the lewer jaw is very promi 
nent. ‘The mouth is very large, which is smaller in Centrarchus. 
I have found representatives of this genus in all the Wester? 
States, from the western parts of New York to the Gulf of Mex- 
ico, and in the southern Atlantic States, but none in the nore 
Atlantic States. The species from the Tennessee River, call 
there Speckled or White Perch, agrees fully with the desrripre 
given by Rafinesque of his Pomoxis annularis, with the mtb 
exception of a golden ring at the base of the tail, which may 
* DeKay has contrived to render the genus Centrarchus of Cuvier still Jess nati 
ral, by introducing into it his Centvarehus fasciatus and obscurus, which truly belong 
to the genus Grystes. See “ Lake Superior,” page 295. 
