228 



U. S. p. E. R EXr. AND SIRVEYS — ZOOLOGY— GENERAL REPORT. 



in advance of the orbit. The fins are of hut moderate development ; the insertion of the 

 ventrals is situated a little posteriorly to the anterior margin of the dorsal. The formula of the 

 rays read as follows : 



D 2, 8 ; A 2, 8 ; C 8, 1, 9, 8, 1, 7 ; V 8 ; P U. 



The scales are large, deeper than long, with radiating furrows upon their posterior section 

 only ; the lateral line following the middle of the flanks. 



The dorsal region is Llackish brown ; a black streak is observed along the flanks, just above 

 the lateral line, extending from a black spot at the base of the caudal, to the extremity of 

 the snout. The inferior region is yellowish white ; minute black dots being spread all over the 

 body. 



List of specimens. 



2. DIONDA PAFALIS, Grd. 



Sptc. Char. — Body anteriorly thiekish, sub-fusiform. Head sub-coniciil, ablireTinted, furming a little more than the fifth o( 

 the total length. Eye sub-circular. Gape of the mouth slightly arched; its angle not reaching a vertical line drawn in advance 

 of the orbit Caudal fin entering five times and a half in the entire length. Insertion of ventrals situated under the anterior 

 margin of the dorsal. Scales miulerate, deeper than long. 



SYX.—Dlondapapdlis, Grd. in Proc. Acad. Nat. Sc. Philail. VIII, I85G, 173. 



The head in this species is rather small, but rounded off upon the snout ; it forms a little 

 more than the fifth of the entire length. The eye is sub-circular ; its diameter entering four 

 times in the length of the side of tlie head. The body is thiekish anteriorly, sub-cylindrical, 

 tapering posteriorly. The dorsal and anal fins are proportionally well developed. The caudal 

 is furcated ; the ventrals are inserted under the anterior margin of the dorsal. The scales are 

 moderate sized, deeper than long. The coloration has been altered to a uniform black subse- 

 (juently to its immersion in alcohol with sundry other specimens. 



List of specimens. 



3. DIOKDA PLUMBEA, Grd. 

 Plate LII, Figs. 21—25. 



Si'Ec. Char. — Bcdy elongated, sub-fusiform, compressed, llciul sub-pyramidal, anteriorly blunt, constituting' the fillli of the 

 total length. Gape of inoutli slightly urclied, its angle not cvtonding ns far as a vertical lino drawn in front of tlic orbit. Tlie 

 eye is large, sub-ci cular. The <uudal fin enters about si.\ times in tlio total length. Insertion of vei.trals situated slightly back- 

 wards of the anterior margin of the dorsiil. Scales moderate sized, deeper than long. Greyish brown above ; whitish or 

 yellowish beneath, with a black spot at the base of the caudal. 



SvN. — IHouilu plumbca, Gnu. in Proc. Acad. Nat. Sc. I'hilad. Vlll, ItiiG, 178. 



