FAMILY PLANIDiE — PLATESSA. 299 



** EYES AND COLORED SURFACE ON THE LEFT. 



THE OBLONG FLOUNDER 



Platessa oblonqa. 

 PLATE XLVIII. FIG. 156. 

 The Spotted Flounder, P. oblmgus. Mitchill, Trans. Lit. and Phil. Soc. N. Y. Vol. I, p. 391. 



Characteristics. Oblong. Smooth. Nearly uniform brown ; occasionally with spots. Caudal 

 fin angulated. Length fifteen to twenty inches. 



Description. Oblong. Length of the head to the total length as one to four and a half. 

 Scales small, orbicular, and deeply imbedded ; they extend far up on the caudal fin. Late- 

 ral line straight from the tail, until it reaches near the tip of the pectoral, when it suddenly 

 rises, curving convexly above it, and then proceeds with a gently concave curve to the upper 

 angle of the branchial aperture. Nostrils double ; the posterior and superior placed imme- 

 diately in front of the dorsal fin. Lower jaw prominent; its sjrmphisis deep and truncate. 

 Eight to ten sharp stout teeth on each side of the lower jaw ; six to eight similar teeth on each 

 side of the upper jaw, and the remaining posterior portion of the jaw filled up with numerous 

 minute teeth. Tongue smooth. Stout hooked teeth on the pharyngeals. The branchial 

 membrane united in the centre, and strengthened by two bones forming the letter V. 



All the rays of the pectoral and caudal fins branched ; those of the remaining fins simple. 

 The dorsal fin commences anterior to the upper eye, and its anterior rays are doubled over and 

 free. This would assimilate it to the Rhombus, but the dorsal and anal do not approach un- 

 usually near the caudal fin. The same feature is noticeable in the anal fin, the anterior rays 

 of which arise almost immediately behind the ventrals, with the vent on the uncolored side. 

 Caudal fin with its central and external rays longest, producing an angular margin ; its rays 

 remarkably stout and ramose. 



Color. Dark olive-green, with somewhat lighter spots on the head and body ; these spots 

 are occasionally distinct, but oftener with no vestige of them. Dorsal, anal and caudal 

 dusky, tinged with sanguineous. The pectoral and ventral of the under side reddish ; above 

 dark olive with dusky bars. Branchial membrane bright olive above. The lower parts white, 

 with a faint blush of pink. Interior of the mouth rosaceous. Pupils black ; irides yellow. 



Length, 19-0. Depth, 8-0. 



Fin rays, D. 88 ; P. 12 ; V. 6 ; A. 66 ; C. 17. 



This species is occasionally larger, but its average size is usually smaller than these dimen- 

 sions. Although the radial formula does not precisely coincide with the fish of Mitchill, which 

 I have cited as a synonime, yet from the extreme difficulty of being accurate in the enumera- 

 tion of the rays, I can scarcely doubt its identity with his species. For the purpose of intro- 

 ducing uniformity into our English nomenclature, I have called the dextral species Flat-fish, 

 and shall restrict the name of Flounder to the sinistral species of this division. 



