Fig. 19.—The Dredge
Although the net, as above described, will answer the requirements of nearly all young collectors, yet there may be some, who, not satisfied with the exploration of the rocks and pools exposed when the tide is out, desire to know something of the creatures that live entirely beyond low-water mark, where the water is generally too deep for work with a hand net. To such we recommend a small dredge that may be lowered from a boat and then drawn along the bottom. A good form of dredge is shown in fig. 19, and a little skill and ingenuity will enable anyone to construct one with the help of our illustration; but, seeing that the best work is to be done on rough bottoms, it is absolutely necessary that both frame and net should be made of the stoutest materials that can be conveniently employed.
Fig. 20.—The Crab-pot
Those who have ever accompanied a fisherman while taking a pull round to examine the contents of his crab or lobster pots will probably have noticed what strange creatures, in addition to the edible crabs and lobsters, sometimes find their way into the trap. These creatures are often of great interest to a young naturalist, and it will repay him to take an occasional trip with a fisherman in order to obtain them; or, still better, to have a crab-pot of his own. The writer has obtained many good specimens by means of an inexpensive trap, on the same principle as the ordinary crab-pot, made from an old metal bird-cage of rather small size. The bottom was removed, and a very shallow bag of thick canvas fixed in its place; and some of the wires were cut, and bent inwards so as to allow the easy entrance of moderately large crustaceans and other creatures, while at the same time they served as a barrier to their escape. Such a trap, baited with pieces of fish, and let down to a rocky bottom, will enable the young naturalist to secure specimens that are seldom seen between the tide-marks; and the animals thus obtained will include not only those larger ones for which the opening was made, but also a variety of smaller creatures that may enter between the wires of the cage. Some of the latter may, of course, escape by the same way as the trap is being hauled up for examination, but this is not so likely to occur if the canvas bottom is of a material so loosely woven that water can pass through it very freely. It will, of course, occur to the reader that the insertion of a stone or other weight will assist in sinking the trap; also that the ordinary door of the cage forms a ready means by which the captives may be removed.
Fig. 21.—An old Bird-cage used as a Crab-pot