PERIODIC GROWTH OF SCALES IX GADID.E AND PLEURONECTID.i:. 375 



and termiuate with a pollack apparently at the commencement of the 

 ninth summer. By means of these tables a comparison may be made 

 as to the number of lines of growth (exceutric lines) formed during 

 successive years. 



Gadus pollachius. 



Xo. of 

 tish. 



2 



4 



3 



6 



9 



2 



2 



1 



1 



Length 

 of fish. 



2-3 cm. 



4-6 ,, 



6-7 ,, 



9-10 ,, 



10-11 „ 



11-12 „ 



35-39 ,. 



45 



60 



Date (month 

 of capture). 



July 



)) 

 Oct. to Dec. 



December 



Xo. of 

 annual rings. 







I. 

 

 2-4 

 „ 3-5 



1st fomiing 13-16 

 15-19 

 15-19 



Xo. of lines of gro\rth (excentric lines) in years. 

 II. III. IV. V. VI. VII. VIII. IX. 



April to .June, 2 complete 23-24 

 April 3 ,, 21 



4 „ 24 



1 84 



June 



26 



30-31 7 — — — 



29 18 2 — — — — 



24 18 22 3 — — — 



25 12 12 11 9 11 10 



In this case the majority of the scales showed much disintegration. 



Gadus mixutus. 



X'o. of Xo. of lines of growth (excentric lines'*, 

 annual rings. Year I. Year II. Year III. 



1 complete 



10-15 



From the preceding tables the age-indices of these varied sizes of 

 Gadus poUachii'sf and Gadus minvtus may be tabulated as follows: — 



In conclusion, I would express my indebtedness to the officials of 

 the Marine Biological Association, more especially to Mr. "Walter 

 Garstang, Xaturalist in Charge of the Fishery Investigations. 



t Compare Cunxixgham, Marketable Marine Fishes, 1896, p. 295. 



NEW SERIES. VOL. VI. — XO. 3. 



2 C 



