of the Island of Trinidad, W. I. 393 



Subfamily. 

 Callichthyin.^:, Bonaparte. 



Genus. 

 Callichthys, linn, (emend.) 



Body oblong, compressed, with the dorsal and abdominal 

 outlines nearly rectilinear and parallel ; the median line of the 

 back behind the first dorsal is bare, or sometimes covered by 

 small and irregular plates. 



Head broad and much depressed : interparietal plate with 

 the breadth and length nearly equal, and with the posterior 

 extension short and obtuse. Nuchal plates with their internal 

 borders contiguous for the entire or greater part of their length, 

 and each of a sub-triangular form, with the posterior margin 

 rounded and parallel, or nearly so, with the dorso-lateral plates 

 which succeed them on the body. 



Eyes very small. 



Mouth small, with the gape sub-circular. Jaws nearly equal, 

 or with the upper slightly projecting when the mouth is closed. 



Teeth on the dentaries very small, compressed, and recurved. 

 The inter maxillaries and vomer appear to be edentate. 



Lips thin, covering the jaws, the lower forming a membra- 

 nous veil reflected backwards and emarginate. Each angle of 

 the mouth is furnished with a double barbie, whose branches 

 are only united at the base. 



Branchiostegal membrane supported by three moderate rays, 

 and a small or rudimentary one. 



First dorsal subquadrate, above the ventrals. 



Second dorsal above the anal, and consisting of a single spine 

 or spiniform plate, which sustains a slender membrane represent- 

 ing the adipose fin of the Pimelodinse ; this spine is preceded by 

 several small plates. 



Anal short. 



