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the interspinous bones. — But our common halibut grows . as large as this be- 

 fore it J passes into the bottom stage; nay, we might expect that it grew still 

 larger, as the adult fish is so much larger than the Greenland species. — About 

 this however, as far as I know, we have no information. 



The fry of turbot and brill has been gathered in considerable numbers, at 

 their pelagic stage as well as at the following stage of their lives, when they live 

 on'the bottom near the shores among the fry of plaice and flounder. 



It has always surprised me that 1 could so easily collect considerable ma- 

 terials of the jjelagic fry of turbot and brill, while the pelagic stages of the other 

 species of flat-fishes are, proportionally, so difficult to catch. 



In the Scandinavian and Danish literature the fry of the genus Rhombus has 

 long been known and partly described (that of the brill hj Malm and ScJii0clte); 

 therefore it cannot be accidental that it has also so frequently been gathered 

 by me. 



This is either solely owing to its inclination to drift along with the current 

 in the surface of the water on warm, calm days, or perhaps the reason may be 

 also to some extent that these fish are larger and less delicate at their pelagic stage than 

 the other flat-fishes, and therefore not so easily overlooked in the fishing-gear. 



In this connection I shall again mention that the fry of turbot and brill goes 

 much farther into our sounds and the Belts than the young plaice which must 

 be said to be missing on our Baltic shores and in the southern parts of the Belts. 

 May not this be connected with a different way of living at their pelagic stage? 



However now this may be, I have gathered the fry of Rhombus in considerable 

 numbers at their pelagic stage as well as at their later bottom stage. It is, as far as I 

 know the literature, the first time that more considerable materials of both species have 

 been gathered together, and as there has been and still is great uncertainty in the 

 determination of these, as well as of the other young fishes of the Rhombus-gmup, I 

 shall here describe their outer a23pearance at their various stages a little more closely. 



When the young turbot and brill at their pelagic stage are c. 15 mm long 

 (somewhat smaller young ones, see plate I, fig. 3 & 7), all the fins are visible, but 

 the pectorals have still embryonic fin rays. The wandering of the eye has com- 

 menced, but the right eye is not yet on the frontal edge. — Both sides are highly 

 pigmented (black), and on the dorsal fin are seen several (often 6) dark spots (or 

 streaks) which spread over the body across the interspinous bones. On the anal fin 

 are seen 4 spots like these. — The brill has a more longish body than the turbot, 

 and the profile of the forehead is of a somewhat different form; in the brill the 

 length of the snout is considerably larger than the diameter of the eye, but in the 

 turbot it is nearly equal to it ; both these characters are found also in the grown-up fish. 



The character which, without leaving any doubt, settles the question of turbot 

 or brill, is, besides perhaps the number of rays in the median fins which already 

 now is greater in the brill, the head of the turbot which is heavily armed with spines 

 and, particularly over the left eye, has a sharp, projecting, angular spiny crest of 

 bone besides rows of spines down the operculum, and several scattered spines on the 



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