342 



Part Tit. — Thirteenth Annual Report 



Each catch was investigated as carefully as possible, but it was difficult 

 always to measure the specimens. Most attention was paid to the flat- 

 fishes. They were the only fishes of value caught during the trip ; a few 

 haddocks and cod and a considerable number of whitings were also taken, 

 but they were nearly worthless, not being in season at that time of the 

 year. Dr Hoek's investigations were therefore confined to the flat-fishes. 

 Of these eight species were represented in the catches of 1893, viz.: — 

 Turbot {Rhombus maximus, L., Dutch, tarbot) ; brill (Rhombus Icevis, 

 Kondelet, Dutch, griet) • sole (Solea vulgaris, Quenst., Dutch, tong); 

 plaice (Pleuronectes platessa, L., Dutch, schol) ; common dab, (Pleuronectes 

 limanda ) L., Dutch, schar) ; flounder (Pleuronectes flesus, L., Dutch, 

 bot) ; scald-fish or smooth-sole (Arnoglossus laterna, Dutch, scharretong) ; 

 and little sole or solenette (Solea lutea, Dutch, dwergtong). 



Of these the sole, the plaice and the common dab were represented in 

 all the seventeen catches made. Only single specimens of the turbot and 

 brill were taken in any haul ; they were absent in the three catches in 

 17 fathoms at a greater distance (about 60 miles) from the coast. 

 Turbot were taken eight times, and the specimens varied in length from 

 20 to 56 centimetres ; brill were caught 7 times, their length ranging from 

 23 to 33 centimetres. The flounder was only three times met with, all 

 in hauls at a very short distance from the coast. They were small 

 specimens, probably from the Zuider Zee, which had passed out with the 

 water through the Ymuiden-sluices. 



Numerous scald-fishes were taken. They are of no commercial 

 importance, but they were extremely abundant at depths of 15 and 16 

 fathoms, about 24 miles from the coast. Solenettes were obtained in 

 nearly all the hauls. This species has until now escaped the attention 

 of Dutch investigators, so that it was previously unknown that this little 

 fish is to be found almost everywhere along the Dutch coast, and at 

 greater distances also. Their size never surpasses 1 2 centimetres \ and 

 Dr Hoek points out that, in many of the cases in which the destruction 

 of small or undersized soles has been complained of, it was not small 

 specimens of Solea vulgaris, but full-grown specimens of Solea lutea that 

 had been for the most part taken. 



In 1894, a large steam- tug, the 1 Hercules ' from Nieuwediep, was 

 placed at the disposal of Dr Hoek in order to continue the investigations ; 

 but it appears the quantity of coals was limited and the work somewhat 

 handicapped. 



During this excursion seventeen hauls were made with the trawl, at 

 about the same part of the North Sea as in 1893, and, as a rule, the 

 trawling was more successful than in the previous year. The trip lasted 

 from July 23 to August 6, and the weather generally was rough and 

 stormy. The trawl was a new one, the iron heads being after the English 

 model, weighing 65 kilogrammes each ; the beam was of ash, and measured 

 about 44 feet. The meshes of the net were 9 centimetres near the 

 mouth, and 6 centimetres near the cod-end. 



The flat-fishes caught in 1894 were the same as in 1893, the only 

 difference being that several lemon-soles were taken in the latter year. 

 This species is called Tongschar in Dutch, and is only rarely observed in 

 the eastern part of the North Sea, at least so far as the Dutch coast 

 goes. * 



Both in 1893 and in 1894 Dr Hoek tried to calculate the medium 

 size of the flat-fishes at each haul. The number of specimens of turbot 

 and brill was small, but in regard to the other three species, the plaice, 



* Heincke says that it is not very rare on the plaice-grounds in the neighbourhood 

 of Helgoland ( iVissenschqftliche Meeresuntersuchungen, I. i. p. 103, 1894). 



