eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 529 



Colomesus Gill, Proc. U. S. Nat. Mus., VII, 1884, 422 (psittacus). 



Type, Tetrodon psittacus Bloch and Schneider. 



Frontals narrow, excluded from the orbit ; postfrontals joined with the frontals; 

 snout obtuse; dorsal and anal short, rounded. 



362. Colomesus psittacus (Bloch and Schneider). 

 "Ostracion tetraodon" Seba, Locupl. Rer. Nat. Thes. Ace. Descr., Ill, 1748, — 



(pre-Linnsean). 

 Tetrodon psittacus Bloch and Schneider, Syst. Ichth., 1801, 505 (Malabar). — 



GtiNTHER, Catalogue, VIII, 1870, 286. 

 Chelichthys psittacus Muller and Troschel, in Schomburgk, Reisen, III, 1848, 641 



(mouth of Waini and Barima). — Steindachner, " Ichthyologische Mittheil- 



ungen," ii, 1861, 141, pi. 4, fig. 2. 

 Colomesus psittacus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 



484. 

 Chelichthys asellus Muller and Troschel, in Schomburgk, Reisen, III, 1848, 641 



(Guiana). 



Twenty-four specimens, 38-89 mm. Sand-bank at Bartica. (C. M. Cat. No. 

 2425a-/; I. U. Cat. No. 12554.) 



Head 3; depth 3.66; D. 10; A. 10; eye 1 in the snout, 4 in the head, 2.5 in the 

 interorbital. 



Three cross-bars on the head, the middle one between the eyes; a triangular 

 spot on the back at the base of the dorsal, a large saddle-shaped spot on the back 

 in front of this, and an irregular spot on the caudal peduncle dorsad, more or less 

 connected with an oval black spot on the caudal peduncle ventrad; a black spot 

 around the base of the anal; another around the base of the pectoral; distal half of 

 caudal black; the spots variable and sometimes fusing with age. 



