88 



Appendices to Fourth Annual Report 



over the winter in regard to the backward position of the fin. It seems 

 probable, too, from this comparison of the position of the dorsal and anal 

 tins, that the latter holds among the fish of both seasons a similar posi- 

 tion relatively to that of the former. This circumstance— that the anal 

 fin holds, as a general rule, a more backward position on the summer 

 herring than it does among those of winter — fairly entitles us, I think, to 

 look upon the suggestion of the difference in relative position of the dorsal 

 fin being distinctive of the fish of these seasons, as substantiated. 



Table XVI. contains the percentage of fish arranged according to posi- 

 tion of the anal fin, as found in the various fishery districts. 



The fact that most of the fish are grouped in those columns which denote 

 a relatively anterior position, rather than in the centre or towards the other 

 extreme, is merely an indication that the range of variation beyond the 

 common ground (second column for the winter herrings, third for the 

 summer) is greater in extent, though more sparingly represented than is 

 the variation towards a forward position. 



] Position of Pelvic Fin. 



The position of this fin may, like that of tho anal, be taken relatively to 

 the total length of the fish, or to the position of tjie dorsal fin. The latter 

 method will be reduced in value if it is considered in connection with the 

 position of the first dorsal ray, for then we have the position of the pelvic 

 made subservient to the variation in length of the dorsal fin, and conse- 

 quently its position relatively either to the body or to the fin as a whole, 

 is not accurately ascertained. If, however, we compare its position with 

 that of the centre of the dorsal fin, we get a more accurate result. The 

 position relatively :tQ the centre of the dprsal fin will here be given, and, in 

 addition, it will be classed under four divisions corresponding to the first, 

 second, third,and fourth quarters of the dorsal fiii, according to its position 

 below these parts. These divisions, of course, are somewhat dependent 

 on the length of the dorsal fin, but the anterior two combined, and the 

 posterior pair taken as one, give the result of 'before' and -behind' the centre. 



The variation of the pelvic fin is found to extend from "505 to "599 on 

 the body length to end of scales, an extent almost the same as that of the 

 dorsal, which leads to the supposition that it follows the variability in 

 position of that fin. 



TABLE (XVII) showing Percentage of Herrings, arranged according to 

 Position of the Pelvic relatively to the Dorsal Fin. 





Divisions of Dorsal 

 Fin. 



irst 

 irter. 



jond 

 irter 



lird 

 irter. 







S-i 



O) 

 Sh 

 -M 

 fl 



hind 

 ntre. 













Wo 





0) 



wo 



Y "Winter,'. " ' . 

 Mature J 



27-4 



'66-6 



"6=0 



0- 



93-3 



1 



•2 



5-5 



Herrings. | 



. Summer, 



. 34:0 



641 



. 1:9 



0- 



\ 



97-5 





•9 



1-6 



( Winter, , 

 Immature J 



30-3 



68-2 



1-5 



0- 



97-0 



1 



•5 



1-5 



Herrings, j 



V Summer, 



31-7 



65-8 



2-5 



0- 



96-2 



2 



•5 



1-3 



It appears that the summer and winter herrings agree in the position of 

 this fin relatively to the dorsal, as do the immature with the mature ; 



