FISHES CYPRINID AE DIONDA SP ADICE A . 



229 



Besides the other peculiarities of structure above alluded to, this species may readily be 

 distinguished from all its congeners by its scales being the smallest so far observed in the genus. 

 The diameter of the eye does not enter quite four times in the length of the side of the head : 

 once, in advance of the anterior rim of the orbit. The isthmus is rather wide and the opercle 

 quite developed. The scales themselves are somewhat variable in their aspect, those of the back 

 and belly being nearly as long as deep, though posteriorly attenuated ; whilst in the lateral 

 line they are deeper than long and sub-elliptical; radiating furrows existing upon the posterior 

 section alone. 



The color is greyish above and whitish or yellowish beneath ; the base of the caudal fin 

 exhibits a black spot. The sides and under surface of the head being silvery. 



References to the figures. Plate LII, fig. 21, represents Dionda plumbea, size of life. Fig. 22 

 is a section of the body across the line of its greatest depth. Fig. 23, a scale from the dorsal 

 region. Fig. 24, a scale from the lateral line. Fig. 25, a scale from the abdominal region. 



List of specimens. 



4. DIONDA 8PADICEA, Grd. 

 PLATE LII, FIGS. 263 . 



SPEC. CHAR. Body slender and sub-fusiform, compressed. Head sub-conical, constituting about the sixth of the total 

 length. Gape of mouth very slightly arched, its angle not reaching a vertical line drawn in advance of the orbit. Eye mode 

 rate, sub-circular. Caudal entering about five times in the total length. Insertion of ventrals situated under the anterior 

 margin of the dorsal. Scale moderate sized, somewhat longer than deep. Reddish brown above ; dull whitish beneath, with a 

 black spot at the base of the caudal. 



SYN. Dionda^spadicea, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 178. 



The head and body by their Blender appearance give this species the general aspect of the 

 preceding one. The head, however, is more conical and the eye smaller, the diameter of the 

 latter entering four times in the length of the side of the head. The scales are somewhat 

 larger than in D. plumbea, being also longer than deep, anteriorly sub-truncated, posteriorly 

 rounded, with radiating furrows upon the posterior section alone. The color is reddish brown 

 above and whitish beneath ; the base of the caudal exhibiting a black spot. 



Iteferences to the figures Plate LII, fig. 26, represents Dionda spadicea, size of life. Fig 27 is 

 a section of the body across the line of greatest depth. Fig. 28, a scale from the dorsal region. 

 Fig. 29, a scale from the lateral line. Fig. 30, a scale from the abdominal region. 



List of specimens. 



