480 Survey of Fishing- Grounds, West Coast of Ireland, \diS)Q—\%d\. 



E, F, and Z are from Donegal Bay, while X is from the east coast of Scotland, 

 and all four examples are females. It will be seen at once that F is much higher 

 than E, while X and Z agree well enough with F in this respect. E, X, and Z 

 in fact represent the ordinary British type, while F is abnormally elevated. 



To compare E and F more closely, it must be remarked that, since both 

 specimens died with their mouths widely opened, the length of the head cannot 

 be very exactly ascertained, though it is evident that the head is considerably the 

 larger in F. The distance from the point where the lateral line reaches the 

 operculum and the end of the caudal peduncle is in E Id'i, in F 18'1, so that 

 the length and height of body, without head and caudal fin, stand thus — 

 E 19-4 X 10-4, F 18-1 X 13. The greatest thickness of the body is 1-6 cm, in E, 

 and 2*35 cm. in F. The latter is therefore, in all respects, the more massive 

 example, as appears further from the weights — E 5^ oz., F 8^ oz.* 



The length of the upper jaw is in E 2'35 cm., in F2-7 cm. ; that of the lower 

 jaw, from the symphysis to the angular, in E2-7, in F3-1. The height of the 

 caudal peduncle is in E 2*3, and F 2*65 cm. 



In E 89 rows of scales cross the lateral line, in F 87 rows, and the fin-ray 

 formulse of the four examples are : — 



A. J). 



H, .... 



F, .... 



X, .... 



Z, .... 



The difference between F and the other specimens thus rests practically on its 

 greater height. There is no indication of structural malformation, unless a very 

 slight irregularity in the curve of the lateral line on the blind side can be cited as 

 such. The dentition is the same in all the specimens, and there can be no doubt 

 that they all belong to the same species. 



Collett remarks, with justice, that the depth increases with the growth of the 

 individual, and it may be that F is an old example, as the appearance of its teeth 

 seems to indicate, which, while for some reason stunted in length of body, has 

 continued to increase in lieight and other dimensions. The conclusion of that 

 author that H. limandoides (Bloch) is the southern branch of H. platessoides (Fabr.), 

 receives considerable support from the examination of northern and southern 

 examples of other flat fish. Apart from the question of fin-ray formula, it is 

 apparent, on comparing specimens of PI. platessa and PI. limanda from Iceland 

 with tliose obtained from our own seas, that these sjiecies attain, in the northern 

 region, a relative depth of body very much greater than their southern brethren, 



* These weights were taken after the specimens, which were preserved at the same time, had been 

 about eighteen months in the same vessel of spirits. 



