180 



U. S. 1-. K. J{. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



List of specimens. 



7. EMBIOTOCA AEGYROSOMA, Grd. 



Spec. Cihr — General form elongated ; head rather Bma'.l, sub-conical, anteriorly rounded. Eyes circular and well developed. 

 Posterior extremity of the ma.\illary reaching a vertical line drawn in advance of the anterior rim of the orbit. Tip of pectoral 

 fins not extending as far as the anterior articulated ray of the dorsal. About sixty scales in tlie lateral line. Six branchiostegala. 

 A brilliant argentine tint over the entire body, thougli made a little darker along the dorsal region by a greyish or purjilish hue. 

 Fins olivaceous, uuicolor. 



SvN. — Embioloca argyrosoma, Gru. InProc. Acad. Nat. Sc. Fhllad. VIII, 1855, 13G. 



The general form of this species has a more elongated appearance, mayhap, than any of its 

 congeners. It is sub-elliptical in profile, the superior and inferior outlines being regularly 

 convex, slighly depressed upon the head, obliq[uely ascending along the insertion of the anal 

 towards a rather slender caudal peduncle. 



The head is rather small, sub conical, rounded anteriorly, and contained four times and a 

 half in the total lengtli. The mouth is of but moderate size, its cleft directed slightly upwards ; 

 the posterior extremity of the maxillar bone not extending as far as a vertical line drawn in 

 advance of the orbit. The lips are of moderate development. The nostrils are conspicuous, 

 situated towards the upper surface of the head, and nearer to the anterior rim of the orbit than 

 the tip of the snout. The eye is circidar and well developed ; its horizontal diameter 

 constituting the fifth of the distance between the tip of tlie snout and the upper edge of the 

 insertion of the pectorals. The opercle is quite large, and much deeper than broad. The sub- 

 opercle is narrow and thin, tapering outwardly and decidedly less conspicuous than the 

 interopcrcle. The brancliiostegals, six on either side, are small and slender. 



A vertical line drawn from the origin of the dorsal fin would pass behind the insertion of the 

 pectorals. The base of the spinous portion is less than the two-fifths of the soft portion. The 

 articulated rays being broken ofi", the precise shape of the fin could not be ascertained. The 

 same is the case with those of the anal ; the entire base of tiie latter is nearly equal to the soft 

 portion of the dorsal, and equal to the length of the head. Its anterior spinous rays are acute 

 and slender. The caudal is deeply furcated, and constitutes about the fifth of the total length. 

 The origin of the ventrals is situated opposite the space between the third and fourth spines of 

 the dorsal ; their tips extend nearly as far as the anterior margin of the anal. The pectorals 

 are broad and well developed ; their tips extending nearly as far as that of the ventrals. 

 Br. VI : VI ; D IX ; A III, 21 ; C 5, 1, 6, G, 1, 4 ; V I, 5 ; P 18. 



The scales are well developed ; they are much larger along the middle of the flanks than on 

 the dorsal, caudal, and abdominal regions. In tlie lateral line they are smaller than in the 

 adjoining series. Six longitudinal rows may be observed between the anterior margin of the 

 dorsal fin and the lateral line, and fifteen rows between the lateral line and the insertion of 



