of the Fisher 1/ Board fur t^cvtland. 373 



at 122 mm. (tlie 2-mm. grouping t'loiii 117-118 to 129-130 being 11, 

 15, 8 I 8, 10, 12, 12, 16), and if the females in excess of this are 

 excluded, and the males between 119 and 122 mm. are added, the 

 average size of the combined group (of 1326 fishes) is 103*5 nun, or 

 only 0'3mm. greater. On the assumption that the spawning season in 

 the region indicated has its maximum about the middle of March, as 

 happens farther south, the fishes composing the group would have an 

 average age of about one year and five months. 



In each collection there are larger fishes belonging to older genera- 

 tions, but the demarcation between these groups is in some measure 

 problematical. With the haul of 31st August the difiiculty is greater, 

 since the sexes were not distinguished in that case, and thus the 

 confluence due to simple variation in growth is increased and com- 

 plicated by the variation in the size of male and female. In the case 

 of the haul of 4th September the curve of the measurements (PI. XVI.) 

 shows a group of females beginning about 130 mm., with the maximum 

 ordinate about 150 mm., and a regular decline to about 165 mm., after 

 which there is irregularity and a slow fall to 235 mm. The curve of 

 the measurements of males ascends from 120 mm., reaches its maximum 

 at about 135 mm., and then declines rapidly to 145 mm., after which 

 it slowly descends to 170 mm. The termination of the third group 

 among the females may be placed at 174 mm., in which case the range 

 extends from 130 to 174 mm., and the average size of the 325 fishes 

 contained in it is 154"0 mm., or 6y\r inches, showing an increment of 

 growth from the females of the previous generation of 48'2 mm. If 

 the limit is placed at the point where the first interruption in the 

 decline of the curves takes place — viz., 164 mm., the average size of 

 the 279 fishes in the group is slightly less — viz., 153*2 mm. 



Tlie range of the males in this group extends from 121 mm. to 

 apparently 153 mm., and the average size of the 145 fishes composing it 

 is 136'9 mm., or 5|^ inches, showing an annual inciement of growth 

 from the males of the previous generation of 34*9 mm., or Ig inches. 



A fourth series of females appears to begin about 175 mm. and to 

 terminate about 201, the demarcation in this case being more doubtful. 

 The 85 fishes comprised within it have an average size of 182"9 mm., 

 or 7| inches, sliowing an annual increment of growth from the 

 previous generation of 28"9 mm. The corresponding males are 

 eighteen in numbei", ranging from 155 to 173 mm., and having an 

 average size of 156" 1 mm., or Gy^^ inches, and thus indicating an 

 annual growth from the previous series of 19"2 mm., or ;^ inches. 



A fiftli group of females, 23 in number, is placed between 204 ai;;^ 

 238 mm., with an average size of 222'8 mm., or 8| inches, and 

 showing an apparent animal increment of growth from the previous 

 generation of 39 9 mm., or 1^^ inches. The increment indicated is 

 greater than in the previous series, wliich shows that the limits of the 

 group are probably not accurately defined, or the proportion of the 

 different sizes not equally represented. One female at 261 mm. probably 

 belongs to a sixth series. 



On IGtli and 19th October two hauls with tlie fine net were made in 

 the northern part of the North Sea, in 60 to 65 fathoms, about sixteen 

 miles south-east of Fair Isle, and therefore about fifty or sixty miles 

 further to the westward than the hauls in August and September. 

 The number of long rough dabs obtained was 1550. The fir.st series 

 comprised 180 fi.shes whose sex was not determined. They ranged in 

 length from 40 to 68 mm., and had an average size of 53'3 mm., or 

 2^ inches. Tlie second series was very distinctly defined. The 

 females, numbering 464, varied in length from 79 to 136 mm., and 



