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 proeorbital. The eye is nearer to the extremity of 

 the oi)erculum 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. Cheek covered with small scales, arranged in 

 nine subhorizontal and in eight subvertical series. Operculum and 

 suboperculiun entirely scaly. 



Dorsal spines verj- strong : the seventh and eighth are the longest, 

 theii" 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 tin. 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. 



A.cara, sp., Heckel. 



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

 which are veiy slightly crenulated posteriorly. Dorsal spines nume- 

 I'ous, 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-Uke. Cleft of the mouth of moderate width, ob- 

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

 on the cheek small. 



Brazil. 



1. Hygrogonus ocellatus. 



Lobotes ocellatus, Ayuss. in Spix, Pise. Brasil. p. 129. tab. 68. 

 Acara erassipinnis, Heckel, Brasil. Fluss-Fisehe, p. .356. 



D. i2. A. l^. L. lat. 37-38. 



Scales on the cheek in about ten series ; pi-aeorbital 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., Cm: 2iPff)te Auim. 



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



Habit Perch-like. 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 %-iUifomi teeth. The 



