DREDGING — TOWING. 47 



Annelides haunt the same places, and some of these 

 are of surpassing "beauty. Many curious kinds of 

 Crabs and other Crustacea, too, and in spring the 

 elegant Nudibranch Mollusca, reward the labour of 

 stone-turning. 



The Univalve Mollusca crawl freely over the 

 surface of the rocks, or roam amid the umbrageous 

 foliage of the weeds that fringe the clear pools ; 

 whither also many of the lithe and slender Worms, 

 and the swimming Crustacea, as the Prawns and 

 their allies, resort. Some of the Bivalve Mollusca 

 buiTOW into the solid rock itself, and the Acorn 

 Barnacles are seated by thousands on its surface. 

 Most of the burrowing Bivalves, liowever, are to 

 be dug out of the sand or mud of the flat shore, 

 and many interesting animals are found on the beds 

 of sea-grass (Zosfera) that grows on such a coast. 

 These are collected by means of a keer-drag, a 

 form of net which the reader may find described, 

 with the mode of using it, in my "Aquarium," p. 56. 



Dredging. — To the same work I must refer for 

 a description of dredging and its prolific results, 

 whereby the bottom of the deep sea is scraped and 

 the varied contents brought to light. Multitudes 

 of animals of the highest interest are procured by 

 dredging, that the shore-collector would never find ; 

 and yet shore-collecting must always be the main 

 resource, at least of the majority. 



Towing. — One more means of obtaining animals 

 remains to be mentioned, — the surface-net. This 

 may be made of stout muslin, in the form of a 

 bag, two feet deep, sewed on a thick brass ring 

 a foot in diameter, which is screwed at the end of 

 a staff six feet long. The staff should be of tough 

 wood, such as hickory or lance-wood. The net is 



