286 POLYCHAETA 



swallowed during the process of burrowing as well as for the 

 purpose of obtaining food, as in the case of the earthworms. 

 Eather nearer the water may be seen little tufts of sand-threads, 

 about an inch high, springing from a short piece of cylindrical 

 sandy tube rising up out of the sand ; this is the head end of 

 the tube of Tcrebella conchileya (Fig. 153). 



Amongst the rocks may be found loose stones of different 

 sizes ; on lifting them up, various kinds of worms may be 

 brought to light, according to the locality, the time of year, the 

 position with respect to the sea, and so on. Polynoe is pretty 

 sure to be present somewhere near low-tide mark ; the number 

 of species is considerable, and their colouring very varied : bxit as 

 the worms have a habit of remaining still on the under surface 

 of the uplifted stone, the observer may easily overlook them. 



Other worms occur below the stones, more or less buried in 

 the sand or mud ; for instance, a small Nereis may be lying in its 

 temporary burrow immediately underneath, and will at once 

 withdraw from the now injured part of the burrow ; while deeper 

 in the mud or sand, especially in rather highly-smelling mud, 

 little red worms are abundant, such as Scoloplos, Nerinc, Capitella, 

 and others. By digging near low water one may find Nephthys, 

 Glycera, and others burrowing or hiding in the soil. 



In rock pools, or sandy stretches amongst rocks kept moist 

 and cool by abundant Fucus, one may see under stones the red 

 or yellow gill filaments of Cirratulus and of Terebellids protruding 

 from their burrows and tubes, while other worms are to be met 

 with in clefts of the rocks, and amongst the roots of Laminaria. 



Still farther out, below low -water mark, where one must 

 wade, can be seen the beautiful branchial crowns of various 

 Sabellicls protruding from their tubes ; but care is necessary on 

 approaching these worms, as eyes are, in many cases, present on 

 the branchiae and a shadow is readily perceived ; then the 

 brightly -coloured tuft disappears, and only a piece of sandy or 

 muddy cylindrical tubing remains to tell where the Sabella has 

 withdrawn. In order to obtain the worms one must dig quickly 

 and deeply before they have been disturbed ; for the tube is of 

 considerable length, and the inhabitant withdraws to the bottom 

 of it. Some of these soft-skinned worms have the power of 

 boring into hard rocks, 1 though by what -means they do so is 

 1 See M'Intosh, Ann. May. Nut. Hist. (ser. 4) ii. 1868, p. 276. 



