PECULIARITIES OF PLAICE FROM DIFFERENT FISHING GROUNDS. 341 



very abundant or very prominent. The spinules on the fin-rays were 

 also more numerous and more regular. The fin-rays are scarcely 

 different from those of the Dalmatia form, but the body is higher and 

 the head apparently a little longer; these, however, are differences of 

 age, the body being higher in the larger specimens, the head longer in 

 the smaller. In the ]Mack Sea specimens, as in those from Dalmatia, 

 the tubercles along the bases of the fins are present, more developed 

 in the former. Again, we find here that the greater development of 

 tubercles corresponds to a colder climate ; the Black Sea is considerably 

 colder, at least in winter, than the Adriatic. The presence of spinulated 

 scales on the fin-rays, as in the plaice, is remarkable. 



On the northern coast of the eastern hemisphere the flounder is not 

 known to occur further east than the White Sea. Smitt states that 

 Lieut. Sandeberg brought specimens from the White Sea in which the 

 body was entirely smooth, with the exception of the spinous tubercles 

 at the bases of the fin-rays, and a few on the head and near the lateral 

 line. They were described as a distinct species under the name 

 Pleuronedes Boydanovii ; but quite similar forms may, according to 

 Smitt, be found in the Baltic. These were apparently individual 

 variations, and it is not clear whether or not the flounder on the whole 

 is as strongly spinous in the White Sea as in the Baltic. 



The flounder is not included in Liitken's Fishes of Greenland, and 

 is not mentioned as occurring on the north-east coast of North America. 

 Yet there is a form, scarcely distinct as a species, in the Pacific, remark- 

 able chiefly for the extensive development of spiny tubercles, but in 

 the character of these tubercles, and in other respects, very closely 

 similar to the European flounder. The chief difference is, that according 

 to the descriptions of Jordan and Goss there are no cycloid scales in 

 the Paciflc form, to which they actually give a distinct generic name, 

 Platichthys stdlatus. This form extends from Point Conception on the 

 coast of California, latitude 34°, to Coronation Gulf on the Arctic coast 

 of America, which is north of latitude 70°, and not very far west of 

 Hudson's Bay. It is difficult to understand why the flounder-like form 

 should be absent on the intervening coasts, or in the intervening rivers, 

 between the north-west coast of America and the coast of Europe. 

 On the Asiatic side of the Pacific the form stcllatus extends southwards 

 to Saghalien, and indeed from the descriptions appears to be the same 

 species as Fkuroncctcs aqKrrimus of Japan. 



Smitt suggests in one passage that the forms which culminate in the 

 plaice and flounder started from one of the three liminula (dab) 

 (jlacialis or cicalricosiis, and considers the latter two varieties to be 

 diverging in the same directions as Jlcsits and i^l^i^icssa. Duncker, on 

 the other hand, considers the plaice the oldest form on account of its 



