THE ANATOMY OF SCALIBEEGMA INFLATUM. 259 



portion of the cesophagus and the anterior portion of the 

 stomach. 



The stomach is lined by columnar cells which are strongly 

 ciliated. Among these there are numerous glandular cells 

 which are swollen with granules of secretion and stain deeply 

 with haematoxylin. There is an exceedingly small amount of 

 muscular tissue in the walls of the stomach. 



The columnar or cubical cells which line the intestine are 

 supported by a thin muscular layer. In the cells of the 

 dorsal and lateral walls of the intestine of large specimens 

 there are very numerous yellow granules, probably chlorogo- 

 genous. There is a well-marked ventral groove, the cells of 

 which are columnar and bear long cilia, running along the 

 whole length of the intestine to the anus (fig. 16). I have 

 traced this groove forwards as far as the level of the fifteenth 

 or sixteenth setae. The function of this groove is probably 

 the same as in Arenicola, viz. to carry backwards along the 

 intestine the digested substances which have been extracted 

 from the sand. In some specimens food particles may be 

 seen in the groove surrounded by a thin covering of mucus. 

 Towards the posterior end of the intestine the whole of its 

 inner wall appears to be ciliated, and the cilia seem to be 

 especially strongly developed in the last few segments. 

 There are two cords situated in the ventral wall of the 

 intestine below the ciliated groove. These, which are best 

 developed in old specimens, are apparently nervous (see 

 p. 268). 



12. Vascular System (fig. 14). 



Danielssen (1859, p. 70) has described and figured some of 

 the principal parts of the vascular system, but as his account 

 is not complete, and is incorrect in some respects, I propose 

 to describe the vascular system as seen in the dissection of 

 my largest specimen (56 mm. long). 



The dorsal vessel arises near the anus, and runs along the 

 whole length of the alimentary canal, breaking up into capil- 

 laries on the pharynx. It is closely adherent to the gut, and 



