96 TRANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



No. 3 on the same figure is a Sedentary Annelid, the little 

 Spirorbis borealis, which makes small spirally coiled white 

 calcareous tubes on the surface of stones, dead shells, and 

 coarse sea-weeds all round our shores. The tube alone 

 looks like a little shell, but it is a worm which builds it 

 and lives in it, and which while alive can protrude from 

 the opening a beautiful plume of delicate branched 

 tentacles, as is seen in the figure (IX., 3). Another 

 common Sedentary Annelid, Serpula, makes larger white 

 calcareous tubes, and is frequently seen in our tanks. 

 These are only a few of the very many kinds of bristle- 

 bearing marine worms or Annelids (for a full list see the 

 report in our " Fauna," by Mr. J. Hornell). Other 

 common species on our shores are the fisherman's lug- 

 worm, Arenicola marina, and the sea-mouse, Aphrodite 

 aculeata, both found burrowing in sand. These and 

 various other kinds are generally to be seen in the shallow 

 table tanks of the Aquarium. Some of the Sedentary 

 Annelids inhabit tubes made of sand grains, and one of 

 the members of the Liverpool Marine Biology Committee, 

 Mr. Arnold T. Watson, F.L.S., has devoted much time 

 and trouble to a careful study of the methods in which 

 these worms build up their very beautiful houses by 

 selecting and cementing together particles taken from the 

 surrounding sand and water. The six little drawings on 

 fig. X. are copied from the illustrations to one of Mr. 

 Watson's scientific papers, and they show the front end 

 of the body and sandy tube of Terebella conchilega, a 

 common Sedentary Annelid found in abundance sticking 

 oui of the sand at low water near Port Erin harbour. The 

 middle figure in each row shows the head of the worm 

 placing sand grains on the top of its tube, like bricks upon 

 a wall, while some of the other figures show how the 

 delicate tentacles capture and convey sand grains and 



