104 
Family LABRACIDA. The Bass. 
We have but two species of this family, the white bass and the” 
brassy bass (Roccus chrysops and Morone interrupta). As far as their 
food is concerned, these are evidently equivalent species, agreeing” 
sara in their general relations, and differing only in their distri-) 
ution. j 
Roccus curysops, Raf. Wutrr Bass. 
This species is of medium abundance throughout the northern 
half of the State,—most common in Lake Michigan. A curious) 
fact of its distribution is its rarity in Fox River and the lakes con-> 
nected with that stream. Indeed, during several days’ active col-) 
lecting in this region we did not see a single specimen, neither 
could we hear of the occurrence of the species in those waters, > 
although we made careful inquiry for it among experienced fisher~ 
men. : 
My notes on its food relate only to eleven specimens, of which 
three, taken at South Chicago, in August, were young, but of un-7 
known size. ‘l'wo of these had eaten only Chironomus larve and 
the larve of a remarkable ephemerid? not yet determined, and the™ 
_ stomach of the third contained only a minute fish. The remaining 
eight individuals had depended chiefly on the larve of May-flies) 
(sixty-nine per cent.). The other important articles of their food 
were twenty per cent. fishes (including one sun-fish— Centrarchide) © 
and eight per cent. isopod Crustacea (Asellus). Several attempts to 
secure food from Lake Michigan specimens were unsuccessful, as, 
being taken in pound-nets, their stomachs were always empty. Those 
studied were from various interior situations in the northern third 
of the State. 
Morons INTERRUPTA, Gill. Streep Bass. Brassy Bass. 
This fish replaces the preceding in the southern half of the State, ) 
the Illinois River forming a neutral zone between the respective 
territories of the,two species. 4 
. The food of six speermens of this species. was studied, all taken 
from the Illinois River from May to October. 
Four of these were young. The smallest, one and a fourth inches 
long, taken at Peoria, in June, 1878, had eaten about equally of 
small Dorysoma cepedianum and Entomostraca,—tforty , per cent.) 
Leptodora and ten per cent. Cyclops. One, an inch and a half in 
length, taken at the same time and place, had eaten only Dorysoma, 
with a trace of Cyclops. The next, one and five-eighths inches in- 
length, had eaten a small undetermined fish and a few Daphnias. { 
The fourth, one and seven-eightl{s inches long, caught at Peoria, in 
October, had eaten only larve and pupe.of Chironomus. | 
The two adult specimens were feeding chiefly upon the larve of. 
Neuroptera,—especially May-flies. An Allorchestes dentata and a few 
small grasshoppers also appeared in the food. 
