20 



U. S. p. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



Tlie color is pale reddish brown above, lighter beneath. The fins are greyish olive, the 

 dorsal being provided with a black patch upon its posterior basal margin. The opercular 

 patch is large, margined posteriorly with a white membranous flap. 



References to the figures. — Plate VI, fig. 1, represents Bryttus albuhis, size of life. Fig. 2, a 

 scale from the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a scale from the 

 abdominal region. 



List of specimens. 



2. BKYTTUS SIGNIFER, G r d. 

 Plate VII, Figs. 5—8. 



Spec. Char. — Body contracted and deep. Nape convex, and snout sub-conical. Posterior extremity of ma:dllary ex- 

 tending to a vertical line drawn in advance of tlie pupil. Insertion of ventrals situated posteriorly to the base of pectorals 

 and the origin of dorsal, their tips overlapping the vent. Sciiles moderate. Reddish brown, lighter beneath than above, 

 dorsal and anal fins provided with a black patch. 



Stn. — Bryttm tignifer, Gkd in Proc. Acad. Nat Sc. Philad November, 1857. 



This species may easily be distinguished from the preceding one by its mouth being more 

 deeply cleft, and its caudal fin more emarginated. The outline of the spinous portion of the , 

 dorsal fin is more arched and the scales somewhat smaller, though, as usual, deeper than long. 

 The scales on the cheeks are smaller than on the opercle, although tlie average difi'erence in 

 size between the two is not so great as in B. alhulus. The posterior extremities of the dorsal 

 and anal fins are nearly even, but do not extend to the insertion of the caudal. 

 Br. V: V; DX, 11; A III, 10; C 3, 1, 8, 7, 1, 2 ; V I, 5 ; P 15. 



Color reddish brown, lighter beneath. The fins being greyish, the dorsal, and occasionally 

 the anal, are provided with a black patch upon their basal posterior margin. The opercular 

 black patch is margined with a white membranous flap. 



References to the figures. — Plate VII, fig. 5, rej)resents Bryttus signifer , size of life. Fig. 6 is a 

 dorsal scale. Fig. 7, a scale from the lateral line. Fig. 8, a scale from the abdominal region. 



List of specimens. 



