12. CICHLA. 303 



the hind teeth in the lower jaw form a narrow band. The jaws are 

 scarcely protractile. 



The space between the orbits is convex, much wider than the orbit» 

 and as wide as the praeorbital. The eye is nearer to the extremity of 

 the operculum than to that of the snout ; its diameter is contained 

 four times in the length of the head and once and a half in the 

 extent of the snout. Check covered with small scales, arranged in 

 nine subhorizontal and in eight subvertioal series. Operculum and 

 suboperculum entirely scaly. 



Dorsal spines very strong : the seventh and eighth are the longest, 

 their length being somewhat more than one-half of that of the head ; 

 the posterior spines are a little shorter ; the soft dorsal is somewhat 

 elevated in the middle and scaly at the base ; the distance of the 

 dorsal from the caudal is only one-half of the depth of the free por- 

 tion of the tail Anal spines shorter but rather stronger than those 

 of the dorsal fin. Pectoral as long as the head ; the outer ventral ray 

 prolonged into a short filament. 



Scales ctenoid ; those of the lateral line are larger than the others, 

 with the single tubes much elongate. 



Nearly uniform blackish-brown : a black spot on the upper half of 

 the root of the caudal ; a small black spot behind the eye. 



11. HYGROGONUS. 



Acara, sp., Heckel. 



Body compressed, oblong, covered with scales of moderate size, 

 which are very slightly crenidatcd posteriorly. Dorsal «pincs nume- 

 rous, anal spines three. Vertical fins enveloped in a coat of scales. 

 Teeth in a band, conical. Anterior prominences of the first branchial 

 arch short, tubercle-like. Cleft of the mouth of moderate width, ob- 

 lique, extending to below the eye, with the lower jaw longest. Scales 

 on the cheek small. 



Brazil. 



1. Hygrogonus ocellatus. 



Lobotes ocellatus, Agass. in Sjnx, Pise. Brasil. p. 129. tab. 68. 

 Acara crassipinnis, Heckel, Brasil. Fluss-Fische, p. 356. 



D.i3. A.^. L.lat. 37-38. 



Scales on the check in about ton series ; praeorbital half as wide as 

 the eye. A black ocellus at the root of the caudal. 

 Brazil. 



The specimen described by Agassiz has an ocellus on the root of the 

 pectoral, and several others along the base of the dorsal. 



12. CICHLA. 



Cichla, pt., Cuv. Bkcjne Anim. 



Cichla, Heck. Brasil, Fluss-Fische, in Ann. Wien. Mm. 1840, ii. p. 408. 



Habit Perch-Uke. Scales small. The spinous and soft portions of 

 the dorsal of nearly equal extent, and separated by a notch ; anal 

 spines three. Each jaw with a broad band of villiform teeth. The 



