DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 839 



Specimens 28 mm. in length are occasionally thrown on the west sands. They are 

 distinguished from the flounders by their larger eyes and more elongated outline, even 

 when the lateral line is invisible. Others 1^ inch long occurred in the trawl on June 7, 

 while somewhat smaller forms were found in the stomach of a gurnard on the 20th of 

 April. 



Pleuronectes cynoglossus, L. (Witch). — Another form characterised by its com- 

 parative thinness, narrowness of body, great breadth of the embryonic fin, and the 

 conspicuous character of the dark olive pigment, was obtained abundantly. It is distin- 

 guished from the young of the long rough dab, by the translucency of the body even 

 after immersion in spirit, and by the nature of the pigment, which is finely dotted 

 along the ventral edge in the young dab, whereas in this form only a few (about 

 five) large isolated patches, blackish in spirit-preparations, occur along the dorsal 

 and ventral margins of the body (PL XVIII. fig. 7). The depth of the embryonic fin 

 exceeds that of the body, and the abdomen is prominent ; the urinary vesicle being 

 very visible posteriorly. A little pigment also occurs on the surface of the abodmen, 

 and the marginal fin is of a faint dull yellow in life. Both sides are similarly coloured. 

 The caudal region is abruptly narrowed, and the notochord proceeds straight outward 

 even when fish is 8 mm. in length. The lower caudal rays are, however, cartila- 

 ginous as well as those above ; all the others are membranous. The otocysts are 

 large and well developed. The head and abdomen, at this time, appear dispropor- 

 tionately large for a body so long and slender. By the development of the hypurals 

 the usual changes are brought about in the tail, and when the fish is 12 mm. long and 

 about 4'5 mm. broad (PL XVIII. fig. 8), the marginal fin is appreciably narrower, while 

 the interspinous elements appear along the edge of the trunk, and inferiorly the body 

 now slants from behind downward and forward, so as to embrace the gut. The ventral 

 fins are not yet visible. Five pigment-patches occur along the dorsal line as before, 

 besides some minute spots at the base of the tail. Inferiorly, on the right side, two 

 touches are present on the abdominal edge, and one at the curve of the rectum 

 superiorly ; three others lie in front of the caudal pigment-spots. On the left side 

 the abdominal patches are somewhat less distinct. A little black pigment also exists 

 on the tip of the jaw, at the ventral edge of its angle and on the prominent area below 

 the pectorals. The right eye is apparently a little in front of the left. The embryonic 

 tail remains with its superior rays, while the inferior rays (forming the main part of the 

 caudal fin) are well developed. Parasitic Caligi are frequently attached to the anterior 

 region. 



When 14 mm. in length (PL XVIII fig. 9), the greatest breadth of the fish, including 

 fins, is about 7 mm. The left eye at this time appears, in profile, above the head, and is 

 distinctly in advance of the right. The pigment-spots on the right and left sides are nearly 

 the same, though those on the right, perhaps, are more distinct ; four patches occur 

 along the dorsal margin and three along the ventral margin of the body. The touches 

 on the abdomen are present, but somewhat altered by the growth of the tissues, and so 



