44 THE MICROSCOPICAL NEWS, 
have the width uniform throughout. The towing line which I used 
is made of linen stay-cord, waterproofed. ‘Though rather thin,‘I 
found it to be quite strong enough for use with both the dredges I 
have described. On one occasion the dredge fouled, and though 
the tide was running at a considerable rate, and the boat twelve 
feet long and a rather heavy one, the line stood the strain for nearly 
ten minutes without showing any signs of breaking. For a dredge 
of larger size, say 18 inches in width, unless used from a boat of 
large size, and in water over ten fathoms in depth, I should use the 
best and thickest linen blind-cord, waterproofed. ‘The use of a 
thick rope is unnecessary for small dredges. When the dredge is 
put into the water, the boat should be pulled rapidly for a minute 
or two; the line being allowed to run slowly through the hands 
until the dredge falls to the bottom ; and as soon as the length of 
line run out is twice or three times the depth of the water dredged, 
the boat may be allowed to drift with the tide, or gently pulled if 
the tide is sluggish. The line should be held in the hands, and let 
go instantly, when a sudden strain indicates that the dredge has 
fouled. Sometimes a smart pull will liberate it; but it is generally 
necessary to re-trace the ground. A good knowledge of the nature 
of the sea bottom is very essential to successful dredging, and if it 
is necessary to engage a boatman, a prelim™ary trial trip should be 
made before finally engaging him, in order to test his knowledge 
and abilities. During my last visit to the Menai Straits, I was very 
fortunate in this respect. Boatmen who collect for public aquaria 
should be avoided, as a knowledge of the desiderata on their part 
too often results in the dredger being taken clear of all the produc- 
tive grounds. A boat provided with a mast and sail, which can be 
taken down and stowed away during the dredging operations, is 
preferable to one provided with oars only. 
A few words, in conclusion, upon the preservation of the speci- 
mens when taken from the dredge. 
Echinoderms, especially Brittle-stars, should be killed by immer- 
sion in fresh water, but many species may be kept alive and their 
habits profitably studied, by putting them into glass bottles of 
various sizes, of which a good supply should be taken in the boat. 
Small bottles may be carried very conveniently in pockets made of 
some strong material, and divided into compartments like a sports- 
man’s cartridge belt. Such pockets may be fastened by means of 
buttons inside the coat. I have found this contrivance more 
convenient than filling my coat and waistcoat pockets with bottles. 
The larger forms of crustacea and mollusca may be put into a small 
basket. For the safe preservation and carriage of large specimens, 
I have found a strong box, into which a large, wide-mouthed glass 
jar fits loosely, a very convenient arrangement. My box opens at 
the top, and the lid is secured by screws. 
