320 



POLYCHAETA 



to its surroundings. 0. conchylega Sars, has a flattened, scabbard- 

 like tube, which can be carried about by its owner. Atlantic. 

 Lumbriconereis has a more or less conical prostomium, without 

 any tentacles, but with large palps : segments 

 without gills. L. fragilis Mull, is reddish or 

 brownish, with a beautiful iridescence ; it is 

 cylindrical, very narrow, and some 5 or 6 inches 

 long ; L. tricolor Jnstn. is much larger. 



Ophryotrocha (Fig. 170) is a small form often 

 occurring in aquaria ; it is chiefly remarkable 

 for the possession of segmentally-arranged girdles 

 of cilia a permanent larval feature. Lysidice 

 ninetta Aud. and Edw. belongs here. 



Fam. 10. Glyceridae. Elongated worms with 

 numerous segments. The prostomium, though nar- 



row, is long, conical, annulated, and carries at 

 its apex four very small tentacles; at its base a 

 pair of palps. Special retractile gills are pres- 

 ent. The armed pharynx is very long, and when 

 protruded appears wider than the animal. The 

 members of this family are without any system 

 of blood-vessels, but the coelomic corpuscles are 

 coloured red. Glycera has four jaws, the parapodia 

 are all alike (Fig. 136, C). G. capitata Oerst. is 2 

 or 3 inches in length, is yellowish in colour, with 

 a dark-reel median line. It may be found 

 burrowing in sand. The setigerous lobes of each 

 foot are coalesced to form one lame lobe with 



o 



pointed apex. The dorsal cirrus is a small wart 

 above the base of the foot. Atlantic and Medi- 

 terranean. A second species, which is much 

 larger and flesh-coloured, also occurs. 



Goniada is distinguished from the preceding 

 by the fact that the parapodia suddenly change 

 in size and character at about one-third the length 

 of the body. The pharynx has numerous para- 

 gnaths. G. maculata Oerst. occurs off our coasts. 



Fam. 11. Sphaerodoridae. The dorsal and 

 ventral cirri of each segment are spherical. 

 The chaetae are usually jointed, and there is an aciculum to each 



Fig. 171. Glycera 

 meckelii Aud. 

 and Edw. with 

 pharynx everted, 

 x 1. (Regne 

 Animal.) 



