228 



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



in advance of the orbit. The fins are of but 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 14. 



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 blackish 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 PAPALIS, Ord. 



SPEC. CHAR. Body anteriorly thickish, sub-fusiforni. Head sub-conical, abbreviated, forming a little more than the fifth of 

 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 moderate, deeper than long. 



Sw.Diondapapalis, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 178. 



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 the head. The body is thickish 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 

 quently to its immersion in alcohol with sundry other specimens. 



List of specimens. 



3. DIONDA PLUMBEA, G r d . 

 PLATE LIT, FIGS. 2125. 



SPEC. CHAR. Body elongated, sub-fusiform, compressed. Head sub-pyramidal, anteriorly blunt, constituting the fifth of the 

 total length. Gape of mouth slightly arched, its angle not extending as far as a vertical line drawn in front of the orbit. The 

 eye is large, sub-circular. The caudal fin enters about six times in the total length. Insertion of ventrals situated slightly back 

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

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



STN. Dionda plumbea, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 178. 



