(47) 
Genus CENTRARCHUS, Cuvier. 
46. Centrarchus irideus (Lac.) Cuv. et Val. Shining Bass. (M. Y. 246 ; 
Nelson, 37.) 
Numerous specimens from the southern part of the state, referable to 
the southern Centrarchus irideus , but not typical specimens of that species, 
being in some respects intermediate between C. irideus and C. macropte- 
rus. Distinct as these two species appear, they may be found to intergrade 
so that they will have to be merged into one. In form of body and size of 
mouth these Illinois specimens are exactly irideus , but the ventral spine is 
more elongate, reaching the first anal spine, and the fins are rather higher 
than is usual in irideus. The dorsal fin in the young specimens has a 
large jet-black spot, strongly ocellated. The larger specimens examined 
have the dorsal plain. Union Co., Johnson Co. 
Genus POMOXYS, Rafmesque. 
47. Pomoxys nigromaculatus (Les.) Grd. Grass Bass, Calico Bass, Bar- 
fish, Bitter-head. (M. Y. 247; Pomoxys hexacanthus Nelson, 37.) 
Generally very abundant, especially in the northern part of the 
state. In the southern part of the state, the next species takes its 
place to a great extent. Peoria, Quincy, Chicago, Rock River, 
Henry. 
48. Pomoxys annularis Raf. Croppie, New Light, Campbellite, 
Bachelor. (M. Y. 247; Nelson, 37.) 
Abundant everywhere in the tributaries of the Ohio and Missis- 
sippi, especially southward. Pekin, Peoria, Quincy ; Wabash R., 
Ohio R., Mud-holes in bottoms, Johnson Co., Union Co., Mack- 
inaw Cr. 
Family ELASSOMATIDiE, (the Elassomes.) 
Genus ELASSOMA, Jordan. 
49. Elassoma zonatum Jordan. (M. Y. 248.) 
A large number of specimens of this singular little fish were obtained 
by Prof. Forbes in ponds and sluggish waters in Union County. From 
these the anatomy of the species has beenpartly made out, and the 
affinities of the genus have probably been ascertained. As suspected 
by me when Elassoma was first discovered, its relations are with Apho- 
doderus , and it will doubtless constitute a separate family, which should 
be placed next to the Aphododeridse. The resemblance of both to the Um- 
hridse probably indicate real affinities. None of Professor Forbes’ speci- 
mens are an inch in length. At the time of collection they were supposed to 
be the young of Aphododerus. In these specimens the black shoulder spot 
is feeble and there are three dark spots at the base of the caudal, verti- 
cally placed, imitating the black caudal bar in Melanura. The fin formula 
