288 REPORT OF STATE GEOLOGIST. 



extent of the larvae of mayflies. A fifth part of the food consisted of 

 other fishes. Some isopod crustaceans had also been eaten. The young 

 fishes live principally on the larvae of dipterous insects. 



Genus MORONE Mitchell. 



Body deep and compressed. No teeth on the base of the tongue, but 

 with teeth near the tip. Jaws about equal. Dorsal fins joined at the 

 base. Anal rays, III, 9. 



MORONE INTERRUPTA Gill. 



Yellow Bass. 



Roceus interruptus, J ordetn and Gilbert, 1882, 8, 530; 1884, i^, 43 J,. 

 pi. 172. 



Body deep and compressed. Depth in the length two and one-half. 

 Head jDointed, the slope from the front of the dorsal to snout steep and 

 nearly straight. Head in the length three and one-fifth. Tongue with 

 a patch of teeth on each side and meeting at the tip ; no teeth at the 

 base. Scales 7-52-11. Dorsal rays IX-I, 11 ; anal rays IH, 8 or 9. 

 The color is brassy yellow, with seven dark longitudinal stripes. Below 

 the lateral line and below the soft dorsal the dark bands cease abruptly 

 and are replaced by others which begin between the ends of those 

 which have just stopped. Anal and caudal fins dusky. This species 

 differs from Roccus chrysops not only in the generic characters given, but 

 in having the dark bands more distinct, and in the general color being 

 yellow instead of white. Length about one foot. 



Lower Mississippi Valley north to southern Indiana. Wabash River 

 in Vigo County (23, '88, 55) ; Brookville, Franklin County (7, 137). 

 Forbes (7^, No. 3, 37) states that in Southern Illinois this species re- 

 places the Roccus chrysops of the northern portion of the State. Its food 

 was found to consist, in the case of the adults, principally of the larvse of 

 neuroptera, especially of mayflies. The young had eaten about equally 

 of entomostraca and small fishes (hickory shad). 



Family SCI.ENID.E. 



Body elongate, our species compressed. Scales weakly ctenoid. Lat-^ 

 eral line present ; continued far out on the caudal rays. No supple- 

 mentary bone behind the maxillary, which slips under the preorbital. 

 Head scaly. No teeth on vomers, palatines, pterygoids or tongue. Anal 

 fin with one or two spines. A large family, mostly of marine species- 

 Represented in our waters by a single species. 



