of the Island of Trinidad, W. L 13 



Yentrals triangular with one spinous and five soft rays. 

 Pectorals rounded. 



The genus which we have now described was first indicated 

 by Drs. Miiller and Troschel in Sir Robert Schomburgh's 

 " Reisen in Britisch Guiana," and afterwards described in more 

 detail in the third volume of the " Horae Ichthyologicse." It 

 was founded on a single species brought from Guiana by Schom- 

 burgh. Its natural afiinities appear to us to be at present not 

 well determined. By Miiller and Troschel it was placed in the 

 family of Scisenidae, and in deference to their opinion we have 

 so retained it, regarding it, at the same time, as the type of a 

 distinct tribe. In the great length of the ascending branches 

 of the intermaxillaries, and the consequent power of protrac- 

 tion of the jaws, it resembles the Meenidoids. The spinous por- 

 tion of the anal is of extraordinary length, and is only equalled 

 by that of the fishes of the genus Etroplus of Valenciennes 

 among the Ctenolabroids, and by some of the Anabantidse. 

 Only a single species of the genus has been hitherto described ; 

 it has been called by Miiller and Troschel, Polycentrus Schom- 

 burghii ; the number of anal rays in that species is thirteen, 

 and the color is indicated by the single word " braun." The 

 species of Trinidad has one more ray than its congener, and 

 difiers widely from it in color. In allusion to the last character 

 we have given its specific name. 



Polycentrus tricolor, Crill. 



Body oblong oval, highest at the fifth and sixth dorsal spines : 

 the head forms one-third of the entire length, and is shorter by 

 an eighth of its length than the highest part of the body. The 

 diameters of the eyes are rather more than a quarter the length 

 of the head ; they are separated from each other by a space 

 nearly equal to one of their diameters, and about the same 



