1 54 



TUBICOLA. 



PAKT III. 



aeration of both liquids, "which form a beautiful plume 

 when expanded, as in fig. 133, which shows the animal 



when out of its tube. What 

 may be called the head is 

 fixed upon the first ring of 

 the body. The mouth has a 

 lip like a funnel-shaped cup 

 with numerous long slender 

 tubular tentacles ; and two 

 delicate arborescent branches 

 or gills are fixed immediately 

 behind the head. The colour- 

 less liquid which occupies the 

 space between the alimentary 

 canal and the ventral wall of 

 the worm, is sent by the con- 

 tractions of the body into 

 the slender tubular filaments 

 round the mouth, which are 

 covered by cilia, whose action 

 continually renews the stra- 

 tum of water in contact with 

 them. The blood in its usual 

 course enters the capillary 

 tubes of the arborescent gills, 

 where it is oxygenized, and, 

 Fig. IBS. TerebeiiaconcMiega-a,iip, a fter being distributed to the 



surrounded by tentacles, b b, all placed 



upon the first segment of the body, c ; different DOrtfl of the body, 



the skin of the back, d, is laid open, ' 



exposing the circulatory system ; e, 



pharynx ; /, intestine ; g. muscles of 



the belly ; h, gland, supposed to be the 



liver ; i, generative organs ; j, feet ; .... . 



k k, gills ; /, heart ; m, dorse-intestinal 1 116 Slender filaments which 



vessel ; ri, intestinal vessel ; n, venous TJP ji i -i r> n 



sinus ; o o, ventral trunk, branching radiate irOm the head OI the 



tubicular worms are flattened, 



sometimes tortuous, always ciliated, and are often barred 

 and variegated by bright purple, green, and yellow tints, 

 forming a rich and gorgeous crown. 



returns to the heart and gills 

 again. 



