FAMILY PLANID.E PLATESSA. 297 



THE RUSTY FLAT-FISH. 



Platessa ferruginea. 

 plate xmi. fig. 155. — (state collection.) 



The Rusty Dab, Platessa ferruginea. Stoker, Report on the Fishes of Massachusetts, p. 141. 



Characteristics. Willi numerous minute rusty spots over the body. Dextral. A series of 

 four white distant rounded spots along the dorsal and abdominal outline. 

 Length twelve to twenty inches. 



Description. Elliptical ; roughened by orbicular scales, which likewise cover the opercular 

 plates. The scales are rounded about the middle of the body, smaller towards the abdomen 

 and tail, and extend to the tips of the caudal rays ; they extend far on and even beyond the 

 eyes, and are furnished with from four to six denticles on their posterior edges ; beneath they 

 are rounded, becoming pointed towards the tail, and destitute of denticulations. The lateral 

 line curves shortly over the pectoral fin, and then proceeds in a straight line through the middle 

 of the tail. The snout produced ; a strong bony ridge separates the narrow space between 

 the orbits, curves upward and backward, and appears to form a continuation with the lateral 

 line. Eyes large, approximated and prominent. A row of small blunt teeth in each jaw, 

 almost obsolete on the colored side ; on the upper pharyngeals, they are arranged in three 

 transverse rows on a disk on each side, each series consisting of from eight to twelve small 

 incurved teeth on each side. Branchial aperture large, and the membrane dilated with six rays. 



The dorsal fin arises above the anterior portion of the orbit, and runs backward to within a 

 short distance of the accessory caudal rays ; the rays of this fin extend beyond the mem- 

 brane, and its tips are white ; they are longest between the thirty-fifth and fiftieth rays. The 

 pectorals nearly equidistant between the back and thorax, rounded ; the first three simple, the 

 remainder branched ; on the uncolored side, they are all simple. Ventrals extending to the 

 origin of the anal. The anal has a horizontal spine before it ; its rays gradually increase in 

 size to the twenty-fifth, when they as gradually diminish to the last, which is opposite to the 

 termination of the dorsal. Caudal rounded, with rays nearly three inches long; all, with the 

 exception of the first on each side, branched. The membrane of all the fins exceedingly 

 delicate and diaphanous ; the opercular membrane almost transparent. Ovary, in the speci- 

 men before me, long and triangular, almost filling up the abdominal cavity, and extending to 

 within three inches of the base of the caudal rays. No air-bladder nor casca. 



Color. Head and body greenish, with numerous irregular, crowded, chocolate or rust-colored 

 spots, giving a rusty hue to the animal. These spots appear to be confined to the body alone, 

 not extending over the fins. A series of four or five distant obscure rounded spots along the 

 dorsal, and a similar series along the abdominal outline. When held up to the light, these 

 spots are deep black, and the whole body pellucid. Beneath white, except the lower margins 



Fauna — Part 4. 38 



