132 NORTH SEA INVESTIGATIONS. 



lyra) I saw only on the Brown Kidges ; a few specimens of scaldbacks 

 also occurred only on the latter ground. Scruff, in the form of Hydroids, 

 was very scarce on both grounds. Alcyonium, or "teats" as the men 

 call it, was abundant, as were starfishes and hermit-crabs, whelks, 

 and whelk spawn. Natica occurred on the Brown Kidges, and its 

 semicircular band of spawn, believed to be turbot spawn by the fisher- 

 men, on the German coast. 



I examined a piece of the "moor-log" which I brought ashore, with the 

 microscope, and saw only vegetable tissue-cells, brownish in colour. I 

 also saw, with the naked eye, some grass-like stalks in it. It is evidently 

 turf or peat. 



I also made a study of some of the waste fish which I brought 

 ashore. There were 105 Trigla gurnardus, Tin. to 13 in. long, and 

 I brought these chiefly to examine the very conspicuous change of 

 coloration which takes place in this species during growth. At first 

 sight the younger and smaller fish might be taken for a different 

 species. They are of a uniform reddish colour, without spots, but 

 not so bright a red as Trigla cuculus. The elements of coloration 

 are the same as in the grey or older stage, namely red chromatophores, 

 with definite outline and rounded form, yellow chromatophores less 

 distinctly defined, black chromatophores, and small granular iridocytes, 

 with indistinct outlines. In the older livery the red elements are 

 diminished in comparative abundance, and all the rest increased. 

 Iridocytes massed together with yellow pigment, but without either 

 black or red, form bright, yellow spots, usually surrounded by a 

 black ring, forming ocelli. Elsewhere the skin is mottled with 

 yellow and black and grey, with red patches here and there. The 

 intermediate stage is at 9 in. in length, in which only a few of the 

 yellow spots are present. 



I also examined the specific characters of the two species of wecver. 

 I had 15 T. draco 9f in. to 12|in. long, and 8 of 5 in. to 9| in. Of 

 T. vipera I had 18 of 2 in. to 4| in. in length. 



A comparison of the smallest draco and the largest vipera, showed the 

 specific characters to be perfectly constant. They are : — • 



(1) Greater vertical depth of body in vipera, especially from the angle 

 of the jaw to the anus. 



(2) Oblique lines of scales in draco, with yellow patches along the 

 sides ; vipera is silvery, without yellow spots or lines. 



(3) Scales longer than broad in draco, broader than long in vipera. 



(4) Two spines on front of orbit in draco, none in vipera. 



(5) Second dorsal in vipera has 24 fin-rays ; in draco, 30. 



The herring and mackerel fishery, at Lowestoft, has a separate part of 

 the harbour, and a separate market to itself, and is of very considerable 



