LAMPKEYS AND FISHES OF INDIANA. 255 



Dr. Forbes has studied the food-relations o'f this species {IJf, No. 3, 

 44). The young up to a length of one inch, subsist on entomostraca. 

 When a length of an inch and a half has been attained, insect food 

 appears in the diet. Later on, insect food predominates. The adults 

 were found to eat fishes principally, although they depend to a consider- 

 able extent on insects. 



Genus LEPOMIS Rafinesque. 



Form deep and comJ)ressed. Mouth moderate or small. Supple- 

 mentary maxillary bone developed or not. Teeth on vomer and some- 

 times on the palatitfies, but not on pterygoids and tongue. Gill-rakers 

 mostly short ; dorsal fin with ten spines ; the anal with three spines. 



The species of this genus are numerous and much alike, and there is 

 great difficulty in identifying them. Attention must be given to the 

 character of the teeth on the lower pharyngeal bones. These bones may 

 be removed by inserting a hook behind the last gill. The teeth are then 

 to be cleaned of the adhering matter and examined with a lens. They 

 are usually slender and sharj); in a few species they are broad and 

 rounded. 



ANALYSIS OF THE INDIANA SPECIES OF LEPOMIS. 



A. Lower pharyngeal bones rather narrow ; the teeth on them coni- 

 cal and sharp. 

 1. Pharyngeal teeth very slender and sharp. Colors usually 

 bright, 

 a. A well-developed supplementary bone behind the maxil- 

 lary ; palatine teeth present ; gill-rakers rather long 

 and stiff. 



b. Scales of the lateral line about forty-eight ; mouth 



large. exjanellus, p. 256. 



bb. Scales of lateral line about thirty-five ; mouth mod- 

 erate, symmetricns, p. 261. 

 aa. Supplementary bone very small or missing ; palatine 

 teeth few or none ; mouth small. 



c. Gill-rakers stiff, not usually very short. 



d. Opercular flap short, about as large as the eye. 



e. Cheeks with blue stripes. ischyrus, p. 261. 

 ee. Cheeks without blue stripes. 



niachrochirus, p. 257;, 

 dd. Opercular flap of the adult becoming very long 

 and conspicuous. 



f. Seales of the lateral line about thirty-five. 



humilis, p. 257. 

 ff. Scales of the lateral line about forty-five. 



pallidus, p. 258. 



