78 DIVERSIONS OF A NATURALIST 



position, gently propelled by the undulating vibratory 

 movement of his small dorsal fin. The male in both 

 pipe-fish and sea-horses is provided with a sac-like 

 structure on the ventral surface in which he carries the 

 eggs laid by the female until they are hatched. 



a. 



FIG. 4. British Marine Worms or (Jhsetopods. 



a, Arenicola piscatorum. Lug-worm largely used for bait by sea-fishermen. 



It burrows in sea-sand and clay as the earth-worm does in soil. Half 

 - the natural size, linear. 



b, Nephthys margaritacea, actively swimming. It also burrows in the sea- 



sand. Natural size. 



c, Eunice sanguinea, a very handsome marine worm (often used for bait) 



which lives in clefts in the submarine rocks and also swims actively. 

 The numerous filaments on the sides of the ringed body are the gills of a 

 rich blood -colour. The figure is one -third of the natural size, linear. 



The shrimper will probably catch also some very 

 young fish fry including young flat-fish about 2 inches 

 long. If he explores the exposed surface of sand near 

 the low-tide limit, he will find a variety of indications of 

 burrowing animals hidden beneath. Little coiled masses 

 like the " castings " of earth-worms are very abundant in 

 places, and are produced by the fisherman's sand-worm, 



