PHYLUM ANNULATA 



457 



a series of longitudinal lines, so as to be divided into seven 

 bundles. 



The setae (Fig. 358) are lodged in sacs, the sctiyerous sacs (see 



Fig. 369), lined by a 

 continuation of the epi- 

 dermis. In the region 

 of the body in which the 

 reproductive organs are 

 lodged some of these sacs 

 are enlarged and glan- 

 dular, and receive the 

 special name of capsulo- 

 genuus glands. 



The enteric canal 

 (Fig. 360) is, as in 

 Nereis, a tube which 

 runs through the entire 

 length of the body from 

 the mouth at the an- 

 terior to the anus at the 

 posterior end. As in the 

 case of Nereis, it lies in a 

 cavity, the ccelome, lined 

 by a thin cellular mem- 

 brane, the peritoneum or 

 cwlomic epithelium, and 

 filled with, a fluid, the 

 coslomic fluid, contain- 

 ing colourless corpuscles. 

 The coelome is divided 

 into a series of chambers 

 corresponding to the seg- 

 ments by a series of 

 delicate transverse parti- 

 tions, the septa or mesen- 

 teries, consisting of folds 

 of the peritoneal mem- 

 brane enclosing muscular 

 fibres. 



The mouth leads into 

 a small buccal cavity. 

 This is followed by 

 a much larger, thick- 

 walled, rounded chamber, the pharynx (ph.). From the wall 

 of the pharynx there run outwards to the body- wall a number 

 of radially arranged bundles of muscular fibres which, when they 

 contract, draw the pharynx backwards, and at the same time 



