THE DIGESTIVE SYSTEM. 135 



the tentacle and down the other. A slender thread is 

 seen to pass through the centre of each tentacle, con- 

 nected with a thickened ring which surrounds the 

 base of the circle ; possibly this is nervous in its 

 character. 



The tentacles are set around a circular mouth, 

 which leads into a funnel-shaped gullet, the walls of 

 which are thick, granular, expansile and contractile, 

 and highly sensitive. From the outer (or upper) side 

 of its margin, there is given off a singular thick band 

 apparently identical in texture with the walls of the 

 gullet, which passing down by the side of this cavity 

 unites with it at a short distance, being free in the 

 gi'eater part of its course, but connected with the 

 gullet at each extremity. The use of this curious 

 band I cannot, after many and careful examinations, 

 discover. It appears equally sensitive with the gullet ; 

 a vertical aspect shows that it is not, as I was dis- 

 posed to imagine, tubular ; and I do not think it is a 

 muscle. It must not be confounded with the rectum, 

 which is quite distinct, though on the same side. 



The gullet passes into a lengthened tube, which 

 after a narrowing, becomes slightly swollen, and pre- 

 sents the same granular texture with minute trans- 

 verse corrugations, as the funnel of the gullet. After 

 another constriction it opens into a long-oval stomach, 

 which occupies nearly the centre of the cell, and for 

 a reason which I shall presently mention, is capable 

 of but little change of position. 



Close to the entrance of the first stomach is the 

 exit, the intestine being inserted in the upper end of 

 this viscus, just behind the extremity of the gullet. 



