116 LIFE BY THE SEASHORE. 



tentacles, pinkish or yellow in colour, and eight short gills 

 coloured by the green blood which they contain. The great 

 head sheath is formed by the dorsal bristles of the anterior 

 segments, but similar though shorter bristles occur on the 

 other segments. The ventral parts of the parapodia are 

 represented by projections bearing curious hooked bristles 

 of remarkable structure. The surface of the skin is 

 roughened by numerous papillae, which in an allied form 

 (Siphonostoma) secrete a jelly-like investment absent in 

 Trophonia. So far as my" experience goes, it is a sluggish 

 animal, not displaying much activity of any kind, but 

 nevertheless it is zoologically full of interest. 



The next family to be considered is that of the Sabellidae, 

 which includes a large number of common and beautiful 

 worms. They usually construct tubes of sand or mud, and 

 are characterised .by the presence of a " crown " of beautiful 

 gill filaments. These are formed by the splitting up of the 

 palps, and are of a beautiful green colour owing to the 

 contained blood. The base of the crown is concealed by 

 the peristomium, which forms a projecting collar. As in 

 Terebellids the parapodia are represented by bristles and 

 booklets, but the booklets are ventral in the anterior nine 

 segments (thorax), and dorsal in the posterior segments 

 (abdomen). We cannot describe even the more common 

 Sabellids, but may take as an example Dasychone bombyx, 

 a worm which is easily recognised by the eyes on its gills. 

 It forms a soft mucoid tube impregnated with particles of 

 sand or mud, and attached to shells or stones. The worm 

 is short (1-1J inches), of a reddish brown colour, and 

 furnished with a beautiful crown of light -coloured gill 

 filaments. When examined with a lens these filaments are 

 seen to bear dark- coloured eyes, arranged in pairs along the 

 dorsal surface of each filament. Owing to the presence of 

 these eyes the worm is extraordinarily sensitive to varia- 

 tions in intensity of light, and disappears into its tube like 

 a flash if a shadow falls on it. Like other Sabellids the 

 worm, if it can be kept alive, is a most delightful inhabitant 

 of an aquarium, where it may be watched protruding its 

 lovely crown from the tube, so that all the filaments are 

 bathed with water. 



Closely related to the Sabellids are the Serpulids, which 



