V. 



WORMS, MOSS-POLTPS, SPONGES, ETC. 



Worms are in a general way not very attrac- 

 tive animals, yet they present much that is at the 

 same time interesting and beaatifbL This is par- 

 ticularly the case with the marine forms, whose 

 barrows can be traced almost everywhere over the 

 expanse of tidal flats which the retreating waters 

 leave behind them. At these times the animals 

 remain well within their habitations, from which 

 they can be readOy extracted throngh the ose of 

 a long-bladed garaen-troweL The many-footed 

 Xereis, whose superb iridescence rivals in metal- 

 lic effect the lustre of the tropical beetles, is of a 

 type of beauty that is distinctively its own ; and the 

 same may be said of the medusa-like Cirratulus (PL 

 8, Fig. 6), of the green Enchone, or of the gordian 

 Amphitrite (Plate 8, Fig. 1>, with its crowu of 

 flesh-colored tentacles and blood-red gills. Some 

 of these forms, like the Serpulse, inhabit more or 

 less permanentiy calcareous tubes of their o^vn se- 

 cretion; others, by exudation of a binding cement, 

 construct their tubes of agglutinated sand-parti- 

 cles. Both of these types are known as tubico- 

 lous worms. To a third group, represented by the 

 beautiful Xereis (PI. 8, Fig. 9) and its allies (Lum- 

 briconereis, PI. 8, Fig. 3, and the brush like Eunice), 



108 



