608 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



trar cli idee of the United States. Genera about 25; species about 120, 

 inhabiting the rivers of Africa and tropical America, the genus Heros 

 extending into the limits of the United States. Those with locate 

 teeth are herbivorous, the rest carnivorous. 



(Cltromide* Giiuthcr, iv, 264-316.) 



* Spinous part of dorsal longer than the soft; gill-rakers short and thick ; teeth con- 

 ical ; body ovate or oblong, covered with ctenoid scales ; anal spines 5 or 

 more ; mouth rather small HEKOS, 327. 



324. HEROS Heckel. 

 (Herichthys Baird & Girard.) . 

 (Heckel, Brazil, Fluss-fische, Ann. Wien. Mus. ii, 362, 1840: type Heros severus Heckel.) 



Body oblong, compressed, somewhat elevated, the form Centrarchoid. 

 Head rather large, scaly on the cheeks and opercles; preopercle entire. 

 Mouth rather small, terminal, low, the jaws equal; maxillary small ; 

 preorbital deep; jaws with a single series of rather stout conical teeth, 

 behind which, in front, is a narrow band of villiform teeth. Gill-mem- 

 branes slightly connected, free from the isthmus; gill rakers short and 

 thick. Scales rather large, ctenoid; the lateral line interrupted and 

 beginning again below, as usual in this family. Dorsal fin continuous, 

 the spiuous part much longer than the soft part, of about 17 rather low 

 but strong spines; soft rays much higher than spines; anal fin similar 

 to soft dorsal but shorter, its spinous part also longer than the, soft, of 

 about G spines; caudal fin subtrimcate, with rounded angles. Species 

 very numerous in Central and South America. (>>w?, hero; the appli- 

 cation not evident.) 



955. H. cynnogiitfatus ( B - & G.) Gthr. 



Brownish, body and soft parts of vertical fins everywhere with small 

 blue spots; sometimes a black spot on middle of spinous dorsal, with 

 another one below it on the back ; a black blotch at base of caudal. 

 Body oval, moderately compressed; profile gently curved ; interorbital 

 region slightly depressed; eyes small, situated rather backward and 

 high up; mouth small, maxillary not reaching orbit; six rows of scah-s 

 on chn-k ; Cms high. Head 3; depth 2. D. XVII, 10; A. VI, 8. Lat. 1. 

 25. llivers of Trxa* and Mexico. 



( fln-ii-htliyx ryantxjiitlatus B. & G. Proc. Acad. Nat. Sci. Phila. vii, 25, 1854: GUnther, 

 iv, 290.) 



