THE SEASHORE 179 



botryoides. But let us begin by making sure of the crumb-of- 

 bread and the purse sponge. 



From sponges we pass to zoophytes, sea-anemones, and other 

 stinging animals (Ccelentera). We should look for some species 

 of Tubularia, with its double wreath of beautiful tentacles ; for 

 the small Coryne, with club-shaped tentacles ; for Sertularia and 

 Obelia, growing on the sea-weed. These should be put into water 

 to see if they are quite alive, which is plain enough when the 

 polyps expand their heads. Sometimes a hermit-crab shows on 

 its borrowed shell a pinkish growth of Hydractinia echinata, a 

 fine instance of division of labour in a colony. From these small 

 creatures one would pass to 

 the polyps of higher degree 

 the sea-anemones, finding 

 besides the beadlet, the wart- 

 let (Tealia crassicornis) and 

 the elegant white or salmon- 

 coloured plumose anemone FlG - 94- Crumb-of-bread sponge (Halichondria 

 , A ,. , 7 ,. ,7 x i^ panicea). EP, exhalant pore. 



(Actmolooa dianthus). rar 



out, attached to the big Laminarians in deep pools, one may find 

 the olive-coloured Anthea cereus, with non-retractile tentacles. 



Among " worms " we should look first for the living film 

 (Leptoplana tremellaris), a leaf -like simple worm about half an inch 

 long seen gliding about on the under surface of stones ; for the 

 ribbon- worms, like the purple '" sea-snake " (Lineus marinus\ 

 often six feet long, and sometimes more than six times that, found 

 far out at very low tide hidden under sea-weed or loosely lying 

 flat stones ; for higher bristle-footed worms burrowing in the 

 sand, such as species of Nereis ; for the related tube-worms such 

 as Pomatoceros (often called Serpula), with a strong keeled 

 limy tube fastened to stones ; Spirorbis, a minute twisted limy 

 tube very common on sea-weed ; and Terebella, as an illustration 

 of those with sandy tubes. Very abundant are the sea-mats 

 (F lustra) and other examples of the Bryozoa or Polyzoa, often 

 somewhat zoophyte-like, often spreading as beautiful encrusta- 

 tions on the stalks of the sea- weeds. The attaching bases of the 

 larger sea-weeds often harbour a dozen different kinds of animals, 

 and should always be carefully examined. 



