196 



Part III. — Twenty -second Annual Report 



series, which extended from 85mm. to 129mm.. the range being thus 

 44mm. The arithmetic average size for the 279 in the series was 

 106'2mm., the mean was 107mm., and the maximum ordinate lOScm. 

 (PI. XII). The remaining six fishes, measuring from 137 to 149mm., 

 represented part of the second series. 



The next collection was obtained on 11th December, 1901, from the 

 grounds seventy-five miles south-east of Sumburgh Head, Shetland, in 

 seventy-five fathoms of water. The number of specimens secured in the 

 small-meshed net was 704. Most of them belonged to one series, 

 although three were represented. The first was not well represented, and 

 was not cut off so sharply from the next series of larger fishes as in the 

 hauls in September and October of the preceding year* 



The measurements, in 1cm. groupings, are given in the Table appended ; 

 and the 2mm. grouping is as follows at the point of division : — 



115-6 117-8 119-20 121-2 123-4 125-6 127-8 129-30 131-2 

 10 11 7 5 1 4 14 21 25 



This series extends from 97mm. to 122mm., a range of 25mm.; 

 the smaller forms are no doubt absent. The arithmetic average size 

 of the eighty-five fishes contained in it was lir5mm., and the mean 

 was 109-5mm. The maximum range in this series in the collections 

 made in October 1900, which included 1553 fishes, was 50mm., and if this 

 be applied in the present case it would make the size of the smallest 

 belonging to it about 72mm., and the mean size on this basis would 

 be about 97mm. 



The next older group begins at 124mm., and apparently extends to 

 180mm. or 182mm., but it is possible it terminates at about 164mm. 

 The two-millimetre grouping from 157mm. to the end is as follows : — 



157-8 159-60 161-2 163-4 165-6 167-8 169-70 171-2 173-4 175-6 177-8 

 14 8647 12 6 4455 



170-80 181-2 183-4 185-6 187-8 189-90 191-2 193-4 195-6 197-8 

 31-13 - 1-21 



Taking the series as ending at 182mm., the range of the 611 fishes 

 composing it amounts to 58mm. ; the arithmetic average size is 142*3mm. 

 and the mean 153mm. There were other eight fishes, the largest being 

 197mm., which evidently belong to a third series. The arithmetic average 

 size is 190"9mm. 



For comparison with the preceding collections taken in the same neigh- 

 bourhood I give here the main features in tabular form, the averages 

 being the actual arithmetical average. 





1st Series. 



2nd Series. 



3rd Series. 



Date. 





























Range. 



Average. 



Range. 



Average. 



Range. 



Average. 



1900. 

 31 August 



mm. 



mm. 



mm. 

 110-162 



mm. 

 140-2 



mm. 

 163 213 



mm. 

 176-8 



4 September 



51-92 



787 



117-155 



136-0 



157-200 



168 9 



16-19 Octr. 



66-116 



877 



119-172 



143-6 



177-197 



182-5 



1901. 



19 May 



85-129 



106-2 











11 December 



97-122 



111 -5 



124-182 



142-3 



185-197 



190-9 



* Loc. ext. , plate ix. 



