THE BRISTLE-WORMS. 119 



sorts of lives, but as most are relished as food by the larger 

 shore animals so most either form tubes or burrows, or seek 

 convenient lurking-places. Though some, like the Phyllo- 

 docids, can swim with ease, in the general case the bristle- 

 worms when they possess any power of locomotion are 

 creepers, using their parapodia as feet. The purely seden- 

 tary forms live on minute microscopic particles, found in 

 water or in sand, but the active jaw-bearing forms are 

 carnivorous. In the resting condition the jaws lie far back 

 in the buccal cavity, but when in use they, with the buccal 

 sac, are rapidly everted, and can be as rapidly withdrawn. 

 The beauty of colouring and of form we have already 

 frequently emphasised. 



In view of the frequent difficulty of identification a few 

 notes on likely habits for the different species may be wel- 

 comed. In rock crevices, or under stones which roof in a 

 cavity, one may expect the paddle-worm (Phyllodoce lamel- 

 Ugera), the green leaf-worm (Eulalia viridis), the creeper 

 (Nereis virens), and other species of Nereis (N. pelagica, 

 N. cultrifera, etc.). But for these smaller species of Nereis 

 the most likely spots are roots of Laminaria, where many 

 other worms also occur. Under stones resting on sand one 

 finds species of Polynoe, Phyllodoce maculata, Sthenelais 

 boa, and TropTionia plumosa ; but Phyllodoce maculata and 

 Sthenelais are as common in sand itself. Stones resting on 

 mud form favourite lurking-places for Cirratulus. By 

 digging in sand one may obtain Arenicola, species of 

 Nephthys, Glycera, Nerine, as well as other forms. Of the 

 tube-dwellers, the numerous Terebellids, the curious Sabel- 

 laria, and the comb- worm (Pectinaria) all form their houses 

 of sand. The Sabellids have usually tubes made of mud,, 

 while the Serpulids make white limy tubes. The excep- 

 tional habitat of Nereis fucata within the shell of the 

 hermit-crab should also be noticed. 



As already noticed, apart from the bristle-worms, other 

 "worms" occur on the shore rocks. A few only of these 

 can be mentioned. There are first some interesting leaf-like 

 flat worms known as Turbellaria, of which a common 

 example is Leptoplana tremellaris, the "living film." It is 

 a charming little creature barely an inch in length, of a 

 delicate brownish tint, and so thin that it is really a mere 



