EIGENMANN: the freshwater fishes of BRITISH GUIANA 445 



Rhinosardinia gen. no v. 



Type, Rhinosardmia serrata sp. nov. 



This genus is Sardinella with the dorsal and ventral equidistant from the tip 

 of the snout, and the maxillary having a strong thorn directed upward and back- 

 ward from its posterior surface near its upper end. 



287. Rhinosardinia serrata sp. nov. (Plate LXII, figs. 3, 4.) 



Type, 85 mm. Morawhanna. (Carnegie Museum Catalog of Fishes No. 

 2443.) 



Cotypes, two hundred and eighty specimens, 60-85 mm. Morawhanna. 

 (C. M. Cat. No. 2444a-2; I. U. Cat. No. 12558.) 



Cotypes, fifteen specimens, 62-77 mm. Mora Passage. (C. M. Cat. No. 

 2445a-/i; I. U. Cat. No. 12559.) 



Head 4.5-4.6; depth 3-3.6; D. 13; A. 15; scales 37-40 in a median series, 

 8-10 between ventrals and the back; ventral serrse 26-28; eye 2.6 in the head. 



Compressed; ventral edge greatly arched, dorsal outline less so; serrse very 



Fig. 39. Maxillary bone of Rhinosardinia serrata Eigenmann. 



strong; mouth small, oblique, the chin almost entering the profile; maxillary- 

 premaxillary border 2.2-2.3 in the head; gill-rakers 1.5 in the eye, 11 + 32. 



Dorsal nearer snout than to base of caudal by one-fifth to one-third the length 

 of the head; origin of dorsal and ventrals about equidistant from the tip of the 

 snout; caudal deeply forked, the lobes 3.2-3.3 in the length. 



Scales firmly adherent, largest just above and in front of the ventrals; on each 

 scale usually a pair of subparallel longitudinal striae, strongest on the posterior 

 part of the sides and on the tail, the striae more numerous, sometimes reticulate, 

 just in front of the caudal; caudal lobes scaled at their base. 



Highly iridescent; no stripes or spots; back dotted; caudal profusely dotted; 

 chin and snout dusky ; dots above base of anal. 



Ilisha Gray. 



Platygaster Swainson, Class. Fishes, Amph., and Kept., II, 1839, 294 (africanus), 

 name preoccupied. 



