124 



ANIMAL BIOLOGY 



this elongation is so marked that they look more like snakes 

 than they do like fishes. But the eels are not the only fishes that 

 show a striking development in one dimension. The flounders, for 

 example (Fig. 93), exhibit a notable growth in a dorso-ventral direc- 



FiG. 94. — Sting ray. (Jordan and Evermann. 

 Page & Co.) 



Courtesy of Doubleday, 



tion. So far has this been carried that the fish is unable to retain 

 a vertical position, and consequently lies on one of its sides. The 

 eyes, which, in very young flounders, are situated like those of the 

 goldfish, on either side of the head, by a twisting of the bones of the 



Fig. 95. — Mackerel. 



(Jordan and Evermann. Courtesy of Doubleday, 

 Page & Co.) 



skull, both come to lie on the same side of the head. Otherwise, as 

 may be seen, one of the eyes would rest on the sand or mud, when the 

 animal is on the sea bottom. Fishes like the skates and sting rays 

 (Fig. 94) have also a much flattened body, but these animals have 



