Family XXI. Cichlid^e. 205 



Heros Heckel, Arin. Wiener Mus., 1840, 362. (Type, Heros severus 

 Heckel, etc.) 



Herichthys Baird & Girard, Proc. Acad. Nat. Sci. Phila., 1854, 

 25. (Type, Herichthys cyanoguttatus Baird & Girard.) 



Body oblong or deep, much compressed; mouth rather small, 

 terminal, low; premaxillary moderately protractile; lower lip with or 

 without a frenum; jaws with a single series of rather stout conical 

 teeth, behind which is a narrow band of villiform teeth; gill mem- 

 branes slightly connected, free from the isthmus; dorsal spines 14 

 to 18; anal spines 4 to 11; caudal fin subtruncate or rounded, the 

 outer rays never produced into a filament; pectoral fin short, its 

 length less than that of head. 



The species of this genus are very difficult to capture with a 

 seine. They are more skillful in dodging a net, running around the 

 end or jumping over it, than are any other fishes I have ever collected. 

 They live in clear, running water, coming out in shallow places in 

 the sunshine. As any one approaches they hasten at once to deep 

 water, and hide among roots of trees or under overhanging banks. 

 After a few minutes they cautiously come out and again proceed 

 to the shallow water. The adult males are provided with a large 

 hump of adipose tissue between the nape and the spinous dorsal. 



KEY TO THE SPECIES OF CICHLASOMA. 

 a. Mouth large, terminal, the lower jaw very page 



strong, 

 b. Anterior teeth in outer series much enlarged, 

 canine-like; lower lip with a frenum; anal 



spines 5 mcuto 207 



bb. Anterior teeth in outer series not canine-like, 

 scarcely, if at all, larger than the lateral ones. 

 c. Anal spines 7 to 9 ; preorbital 4 in head ; post- 

 orbital 2,' u . 

 d. Lower jaw strong, mandible 2 in head; 

 anal spines 7 or 8 ; lower lip without trace 



of a frenum salvini 207 



dd. Lower jaw less strong, mandible 2% in the 

 head; anal spines 9; lower lip with an in- 

 complete frenum hcdricki 208 



cc. Anal spines 4 to 6. 

 f. Body elongate, depth 2% to 2^. 

 g. Sides with 4 to 7 ocellated, vertically 

 expanded black spots below dorsal fin; 

 depth 2% pavonaceum 209 



