]56 DORAS COSTATUS. 



shall now refer it, mentioning any discrepancies as 

 they occur, in their proper places. 



Doras costatus, Lacep. ; The Mailed Doras. 

 — Le Doras a cotes osseuses, Valenc. xv. p. 268. — 

 Saurauwari, Macusi Indians; Yarauira, L. Geral. 

 Schomh. Dratcings^ No. 41. 



This species seems distinguished from the others 

 in the Collection by the much stronger armature of 

 its spines and plates, and by the strong spear-shaped 

 process which runs from the gill-aperture along 

 the sides. The costal plates are in number thirty, 

 each, except the three first, furnished with a strong 

 hooked, lance-shaped spine; the plates are simply 

 granulated on the surface. Mouth furnished with 

 six cirrlii ; two on the upper jaw longest, reaching 

 to the first costal plate ; four on the lower shorter, 

 the first scarcely more in length than one-third of 

 that wliich accompanies it. Our fish was a female, 

 and in length is about ten and a half inclies. 



The formula of tlie fins given by (1.) Schom- 

 burgk; (2.) Gronovius, pi. v. figs. 1, 2; (3.) Han- 

 cock, Zool. Journ. iv. p. 242; (4.) Valenciennes; 

 and (5.) as counted in specimen : — 



From these apparent discrepancies, supposing all 

 the authors to have described the same fish, it is 

 * Preter nonnula mimora utrlnque liberalia. 



