of the Island of Trinidad, W. I. 19 



Ventrals triangular, with one spinous and five soft rays. 



The genus which we have above characterized was firet indi- 

 cated under the name of Cychlasonia by Mr. William Swainson, 

 in 1839, in his " Natural History of Fishes, Amphibians, and 

 Eeptiles, or Monocardian Animals." About a year later, Mr. 

 Jacob Heckel published a very important Memoir on the fishes, 

 which are comprised in the family Chromididse. In that 

 work he established, among other genera, one for which he 

 used the name of Acara, a vernacular term by which some 

 species of the genus are known in South America. Mr. Heckel 

 embraced in this genus, those fishes which had been described 

 by Bloch as Perca bimaculata, Labrus punctatus, and Sparus 

 Surinamensis, and also the Chromis Nilotica of Cuvier, C. Bra- 

 ziliensis of Quoy and Gayward, C. taenia of Bennet, Sparus 

 Desfontaines of Lacepede, and Lobotes ocellatus of Spix. Mr. 

 Swainson took as the type of his genus the Labrus punctatus, 

 and refers to the figure given by Bloch : — that species is indeed 

 the only one mentioned by him. As it is a true Acara, the lat- 

 ter genus is consequently synonymous with Cychlasoma, and in 

 accordance with the law of priority, the Swainsonian name 

 must be adopted as that of the present genus. 



The characters given by Swainson to his genus are not very 

 satisfactory, and even incorrect in some respects. He chiefly 

 distinguishes it from the genus for which he retains the 

 name of Chromis, by the rounded caudal fin, and by the large 

 pectorals, which are also rounded, assigning to Chromis a 

 lunate caudal, and pointed pectorals and ventrals. But Swain- 

 son's Chromis is rather synonymous with Geophagus of Heckel, 

 for the only species which are referred to it are those fishes 

 which were described by Bloch as Labrus melanogaster and 

 Sparus Surinamensis, the latter of which is a true Geophagus, 

 although placed by Heckel in his genus Acara. Swainson also 

 states, as one of the characters of Cychlasoma, that the " lateral 

 line is abruptly bent ;" this statement certainly does not con- 



