of the Fishery Board for Scotland. 



197 



If. however, the series ends at 164mm;, then the average size of the 

 second group would be 139 9mm., the mean size 144, and the range 

 40mm. ; the third group would have a range of 32mm., an average size 

 of 174*1, and a moan of 181mm. 



The differences between the average size of the various groups as shown 

 above are as follows : — 



1st to 2nd. 



57-3 

 55*9 



20-8 [45-3J 



2nd to 3rd. 



36-6 

 32-9 

 38-9 

 48-6 



In the December haul the first and third series were very imperfectly 

 represented (see PI. XII.), and the averages given do n t correctly 

 show the proper sizes. The figures in brackets indicate the difference of 

 the corrected means. 



Collections of the Norway Pout were also made at various times a few 

 miles off Aberdeen in the deep water known as the Dog Hole, the depth 

 varying from about fifty to about seventy fathoms. 



The first was on 28th June, in sixty-five fathoms, eleven miles off ; the 

 bottom temperature was 48*2° F., and the surface temperature 5 2 '5° F. 

 The number of specimens procured was 141. One of those was a very 

 small one, measuring 27mm., no doubt spawned some months earlier. 

 The next series comprised 131, ranging in size from 125mm. to 172mm., 

 the range being 47mm.; the arithmetical average size was 150*2mm., 

 the mean 148*5mm., and the maximum ordinate 14'5cm. There 

 were six in a third group, ranging from 178 to 194mm., with an average 

 size of 187"2mm., the mean being 186mm. Other three probably formed 

 a fourth series, the sizes being 210, 215, and 222mm., and the average 

 212-3 mm. 



In the next collection, on 30th July, in sixty-two fathoms, the bottom 

 temperature being 57° F., and the surface temperature 58 "6° F., 350 

 specimens were taken, all belonging, apparently, to the same series. The 

 range of sizes w r as from 120mm. to 184mm., or an extent of 64mm. ; the 

 arithmetical average was 155-lmm., the mean 152mm., and the maximum 

 ordinate 15 '5 mm. 



The third lot was got on 21st August, in fifty-eight fathoms, the surface 

 temperature being 55-9° F., and they numbered 218 specimens. Two, 

 possibly three, series, were present. The first comprised three fishes, 

 measuring 67, 81, and 83mm. The second included 214, from 130mm. 

 to 189mm., the range being thus 59mm. ; the average size was 158 "8mm., 

 the mean 159*5, and the maximum ordinate 16cm. 



On 3rd September, the fourth collection was made in fifty-eight fathoms 

 in the same locality, the bottom temperature being 53° F„, and the surface 

 temperature 53*2 ;> . Most of the fishes in the small-meshed net escaped, 

 owing to a hole in it ; the number of Norway Pouts obtained was fifteen, 

 ranging from 132 to 168mm., the average size being 156 9mm., the mean 

 150mm., and the maximum ordinate 16cm. 



A few days later, on 10th September, eight specimens were taken in 

 Aberdeen Bay, measuring 76, 77, 83, 85, 87, 91, 93, 94mm. respectively. 

 The average size was 85'7mm., the mean 85, and the maximum ordinate 

 9cm. 



The next collection at the Dog Hole was on 16th December, in fifty- 

 seven fathoms, the bottom temperature being 46*2° F. The number of 

 specimens taken was fifty-four, belonging to two series. The first included 



