188 



Part III. — Twenty-fourth Annual Report 



Dornoch Firth. 



In the Dornoch Firth some collections of small plaice were also 

 obtained, the particulars of the measurements being given in Tables 

 [V. and VI. On 7th December, 1904, a haul in from 4 to 9 fathoms 

 yielded 182 plaice. The smallest ranged from 59mm. to 98mm. ; there 

 were 19 between these sizes. There were also 13 measuring from 

 125mm. to 145mm. The remainder measured from 173mm. to 472mm. 

 The first group is evidently the fish of the year ; the limits of the other 

 series are not certain. On 9th February, 1905, another haul with the 

 fine-meshed net, in from 5| to 10 fathoms, yielded 355 plaice, ranging in 

 length from 5cm. to 16cm., and distinguished into two well marked 

 groups. The first included 283 specimens, measuring from 52mm. to 

 99mm. (2 T ^-3| inches), or it might possibly be 108mm. (4J inches), the 

 maximum number being around 7cm. (see fig. 4a, pi. XII.). The average 

 length was computed, on the former limit, at 74mm., or very nearly 

 3 inches. If at the larger limit, the average size would be 74'5mm. 



Grouped in centimetres, the measurements are as follows : — 



5 6 7 8 9 10 11 12 13 14 15 16 

 8 59 115 78 19 6 7 14 21 19 8 1 



The smaller series are obviously fish of the previous spawning, and 

 about 10 or 11 months old. 



In the second, older series, comprising 72 plaice nearing the end of 

 their second year, the greater number are grouped about 13cm. to 

 14cm. (5|— 5| inches), the mean size being about 133cm., or 5| inches, 

 and the apparent growth from the previous series amounts to about 

 6'5cm. (2£ inches); but the representation of the larger fishes may not 

 be perfect. 



In another haul on the 31st of March, or about 52 days later, but in a 

 different year, viz., 1904, the second series is represented by 29 specimens, 

 ranging from 112mm. to 196mm. (4|-7| inches), as follows, in centimetre 

 grouping, the mean size being about 14'5cm. (5 J inches) : — 



9 10 11 12 13 14 15 16 17 18 19 20 

 1-1173 6 8111- 



These may be regarded as two years of age (fig. 4b, pi. XII.). 



The same group is represented in other collections, as given in Table 

 VI., but only by a few fishes, viz., in October, November, and December. 



In a haul taken on the 22nd October, 1903, in from 8 to 13 fathoms 

 of water, the 363 plaice which were caught were measured. Though the 

 small-meshed net was employed, the smallest plaice caught was 164mm,; 

 the great bulk of them formed a group between 20cm. and 29cm., with 

 the maximum from 23cm. to 26cm. These fish were approaching their 

 fourth year. 



Annan. 



A few collections of small plaice in April, 1904, were sent to me by 

 Mr. George Bryson, Annan, which had been taken by shrimp-net in the 

 Solway, on the ordinary shrimping grounds. It will be seen from Table 

 IV. that an early series of fish, about one year of age, is represented, 

 most distinctly in the collection on the 23rd of the month, and also a 

 second series, less distinctly marked off from the third, and again best 

 shown in the collection on the 23rd. They indicate the same feature as 

 shown in the previous paper dealing with the growth of the plaice, that 

 the rate of increase in the Solway is slow. 



