250 REPORT OF STATE GEOLOGIST. 



of the ventrals. When the length has become about four inches, the 

 vent is near the isthmus.* 



Family CENTRAECHID^. 

 FRESHWATER SUNFISHES. 



Body usually deep and much compressed ; covered with usually ctenoid 

 scales. Lateral line developed, the row of pores not extending on rays 

 of caudal fin. Mouth terminal, the maxillary often provided with a 

 supplementary bone. Vomer furnished with teeth. None of the teeth 

 of the jaws enlarged. Pseudobranchise indistinct, covered with skin. 

 Dorsal fin with six to thirteen spines. Anal spines three to eight. 



A family of about ten genera and twenty-five species of fishes which 

 are confined to the fresh waters of North America. 



ANALYSIS OF THE GENERA OF CENTRARCHIDiE. 



A. Anal fin nearly as large as the dorsal ; its soft rays at least fifteen 

 in number. 

 1. Spines of anal seven or eight ; its soft rays fifteen. 



Gentrarckus, p. 251. 

 2. Spines of anal six ; its soft rays seventeen or eighteen. 



Poinoxys, p. 251. 

 AA. Anal fin considerably smaller than the dorsal ; its soft rays not 

 more than twelve. 

 3. Teeth on tongue and pterygoids. 



a. Anal spines usually six. AmblopUtes, p. 253. 



aa. Anal spines three. Ghcenobryttus, p. 254. 



••■Family ELASSOMATID.E. 



Size very small. Body deep and compressed, covered with relatively large cycloid scales. 

 Strong teeth on ja-ws and a few feeble ones on the vomer. Gill-membranes broadly united 

 across the isthmus, but free from this. Ventral rays I, 5. 



Genus ELASSOMA Jordan. 



Upper jaw protractile. Mouth small and very oblique. Scales on the cheeks and the 

 opereles. Gill-rakers short. Lateral line not developed. Dorsal with four spines, the anal 

 with three. Two species known at present. 



Elassoma zonatum Jordan. 



Body deep and compressed. Depth in length three and one-half, the outline considera- 

 bly arched above. Head in the length three. Mouth small, very oblique, the lower jaw pro- 

 jecting. Dorsal rays V, 9; anal III, 5. Lateral line wanting. Scales in a longitudi- 

 nal row about forty. Color olive, with about ten dark bars crossing the body; these wider 

 than the interspaces. A dark spot on each side below the dorsal. Length about one and 

 one-half inches. Resembles a young sunfish. 



Swampy regions from Louisiana to S. Illinois. May be expected to occur in Southern 

 Indiana. 



