350 



VERTEBRATES : FISHES. 



PLEURONECTIDyE, OR FLOUNDER FAMILY. This Fam- 

 ily comprises fishes which have the body flat, being com- 

 pressed vertically, both eyes on the same side of the head, 

 sides of the mouth unequal, and a dorsal extending the 

 whole length of the back. The side upon which the eyes 

 are placed is always uppermost when the animal is swim- 

 ming, and is deeply colored ; while that on which the eyes 

 are wanting is always whitish. They have no natatory 

 bladder, and seldom quit the bottom. The want of sym- 

 metry between the two sides of the fishes of this family 

 Fig. 226. is seen in no other verte- 

 brates. About one hundred 

 and thirty species are known, 

 all of which are marine. 



The Genus Platessa con- 

 tains the Flounders proper, 

 Flounder, B. piana, Mitch. which are from six to twen- 



ty-five inches long. Turbots and Soles are representa- 

 tives of genera closely allied to the preceding one. 



The Genus Hippoglossus embraces the Halibuts, which 

 have the eyes and color on the right side. 



The Halibut, H. vn/garis, Cuv., of the North Atlantic, 

 is from two to eight feet long, ashen-gray on the right 

 side, white on the other. It attains the weight of six 

 hundred pounds in some cases. 



CYCLOPTERID.'E, OR LuMP-FisH FAMILY. This Fam- 

 ily comprises fishes whose 

 ventrals are united into a 

 disk or cup-shaped form. 

 By means of the disk, these 

 fishes are able to attach 

 themselves to the surface 

 of the rocks with great 

 Lump-Fish, c. lump. Linn. firmness. The Genus Cy- 



cloptcrus- contains the Lump-Sucker, C. lumpus, Linn., 



