202 U. 8. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



jaw by a broad frenum. The nostrils are large and situated close to the anterior rim of the 

 orbit. The position of the eye is quite elevated, being of medium size, sub-circular, having its 

 horizontal diameter comprised a little over four times in the length of the side of the head. 

 The scales on the cheeks are very crowded, disposed without much regularity. On the 

 opercle five rows may distinctly be counted ; tliey are smaller on the sub-opercle. The branchi- 

 ostegal rays are six on either side and well developed. 



A line drawn vertically from the origin of the dorsal fin passes behind the base of the 

 pectorals. The spinous portion is composed of eleven rays, occupying nearly two-fifths of the 

 base of the entire fin. Its upper outline is sloping from the first to the fifth spine, whence it is 

 nearly straight to the eleventh ; from the anterior articulated ray backwards it is regularly 

 descending. The articulated rays bifurcate twice. The caudal fin is contained a little more 

 than five times and a half in the total length. Its middle rays exhibit a bifurcation of the fifth 

 degree. The base of the anal enters about four times and a half in the total length. There are 

 three spines at its anterior margin, the second and third nearly as long as the articulated rays. 

 Then, in the male, the fin is separated into two portions by a flattened and sub-triangular ray, 

 anteriorly of which the other rays are swollen and their membrane thickened as in Einhiotoca 

 and other genera of the same family. The articulated rays, however, are mostly all divided. 

 The rays adjoining the flat triangular one are more or less irregular and exhibit nuraerijus sub- 

 divisions. The base of the anal extends a little more backwards than that of the dorsal. The 

 insertion of the ventrals is situated under the vertical line of the third dorsal spine. These fins 

 are broadly developed, extending beyond the vent but not to the anterior margin of the anal, 

 and their rays exhibit a partial bifurcation of the fifth degree. The pectorals are well developed, 

 tbeir extremity reaching the vertical line of the second articulated ray of the dorsal. The rays 

 bifurcate three times with traces of a fourth. The formula of the fins is : 



Br. VI : VI ; D XI, 24 ; A III, 7 -|- 1 -f 16 = 24 ; C 4, 1, G, 6, 1, 5 ; V I, 5 ; P 1, 26. 



The scales (figs. 3 — 5) are of moderate development, deeper than long, rounded upon their 

 superior, posterior, and inferior edges, and sub-truncated anteriorly. Their shape is subjected 

 to great variations in the lateral line and on the abdominal region. This is particularly the 

 case along an area opposite the base of the anal, where they are at the same time much smaller 

 than on any other region. On the other baud, on a vertical area immediately above the 

 triangular spine of that fin they assume a disproportionate size. Along the base of the rays 

 constituting the posterior portion of the same fin, scales may be observed of an elongated shape, 

 forming a double row anteriorly. The lateral line is formed of about sixty-eight scales ; seven 

 or eight longitudinal rows may be counted between the latter and the dorsal groove, and about 

 twenty-ibur rows on the line of greatest depth below the lateral line. The dorsal groove 

 extends from the eighth dorsal spine to about the ninth articulated ray ; the sheath above is 

 composed of three irregular series of scales, variable in size, tapering to one row and assuming 

 a more oblong shape. 



The ground color above the lateral line is bluish grey or olive, somewhat mottled. The sides 

 are silvery with a golden reflect, particularly on the sides of the head. Irregular and, mayhap, 

 indistinct transverse bands descend along the flanks from the dorsal region. The dorsal, caudal, 

 anal, and ventral fins are olivaceous or yellowish grey. The pectorals are yellowish or straw- 

 color. 



