310 CHROMIDES. 



anteriorly with long, setiform, closely-set prominences. Scales on the 

 cheek in five or more series. 

 Brazil and Guiana. 



1. Chaetobranchus flavescens. 



Heckel, I. c. p. 402. 



D. ^. A.:^. L. lat. 26. 



The height of the body is one-half of the total length (without 

 caudal) ; the maxillary extends to below the anterior margin of the 

 eye. Scales on the cheek arranged in six series. The length of the 

 dorsal spines behind the fourth is only two-sevenths of that of the 

 head. A black lateral spot ; two bluish convergent stripes from the 

 mouth to the eye ; vertical fins with transverse or oblique streaks. 

 (Heel:) 



Rio Negro. Rio Guapore. 



2. Chaetobranchus bmimeus. 



Heckel, I. c. p. 40.5. 



D. i|. A. ^. L. lat. 26. 



The height of the body is three-eighths of the total length (without 

 caudal) ; the maxillary does not extend to the vertical from the anterior 

 margin of the oyo. Scales on the cheek arranged in five series. The 

 length of the dorsal spines behind the fourth is one-third of that of 

 the head. A black lateral spot ; two bluish parallel lines fi-om the 

 mouth to the eye ; vertical fins with transverse or oblique streaks. 

 (EecTc.) 



Rio Negro. 



3. Chaetobranchus robustus. 



D. if. A. ^. L. lat. 25. L. transv. 2i. Vert. 13/13. 



The height of the body is four-ninths of the total length (the 

 caudal not included) ; the maxillary does, not extend to the vertical 

 from the anterior margin of the eye. Scales on the cheek arranged 

 in five series. The length of the twelfth dorsal spine is contained 

 twice and a third in that of the head. 



Guiana. 

 a. Eleven inches long. Guiana. Presented by Sir R. Schomburgk. 



Bescrij^tion. — The greatest depth of the body is below the sixth 

 dorsal spine, and four-ninths of the total length (without caudal), the 

 length of the head nearly one-third. The width of the interorbital 

 space is not quite twice the diameter of the eye, and two-fifths of 

 the length of the head. The free portion of the tail is half as high, 

 and one-third as long, as the length of the head. Snout broad, 

 obtusely conical, its length being once and a half the diameter of 

 the eye ; praeorbital as wide as the orbit. Cleft of the mouth oblique, 

 with the lower jaw slightly prominent ; the free margin of the lower 



