380 Synopsis of the Fresh Water Fishes, 



vey a true impression, and is even erroneous, as the lateral line 

 is interrupted at the posterior part of the body, towards which 

 the anterior portion of the line is conducted in a direction 

 nearly parallel with the back, and is abruptly discontinued at 

 a point under the middle of the soft portion of the dorsal, or 

 near its posterior termination, and where the constriction of the 

 body commences. The only genus of Chromidoids possessing 

 a lateral line, which could be correctly described as " abruptly 

 bent," is the restricted Cychla of Bloch. 



The other characters given in the diagnosis of the genus by 

 Swainson, apply almost equally well to several other genera of 

 Chromididse. His name itself is also objectionable, but the 

 law of priority renders it imperative that it should be retained. 



Several species appear to have been referred by Mr. Heckel 

 to his genus Acara, which are not congeneric with the majority 

 of his species, or with those lie first describes. The Sparus 

 Surinamensis has been referred by Drs. Miiller and Troschel 

 to lleckel's genus Geophagus, and is even regarded by them as 

 the same as his Geophagus megasema. The species of the Old 

 World that have been referred to Acara, when critically ex- 

 amined, which Mr. Heckel does not seem to have possessed the 

 opportunity of doing, will probably be found to belong to a 

 distinct genus. 



The genus Cychlasoma, as we have restricted it, will include 

 only those species whose bodies are covered by rather large 

 scales, whose cheeks have three or four rows, and which have 

 the greater portions of the vertical fins scaleless, only the bases 

 being covered ; the forehead is also generally straight or con- 

 vex, and the eyes large. "With these characters, that species 

 which Mr. Heckel, in his memoir on the new fresh-water fishes 

 of Brazil obtained by the traveller M. Natterer, has described 

 as the Acara crassispinis, will also be excluded : this species 

 appears to be generically distinct from both Cychlasoma and 

 from Astronotus of Swainson, the latter of which is represented 

 by the fish named by Cuvier, and described by Agassiz, as 



