AC ALE PILE. 



tentacula, which probably assist in introducing the food into the 

 stomach. 



In Cassiopea Borbonica, the principal agents in procuring 

 nourishment are numerous retractile suckers, (Jig. 28, a,) terminat- 

 ing in small violet- F/g.28. 

 coloured discs, which 

 are dispersed over the 

 fleshy appendages to 

 the under surface of 

 the body ; the stem 

 of each of these suck- 

 ers is tubular, and 

 conveys into the sto- 

 mach nutritive mate- 

 rials absorbed from 

 animal substances to 

 which they are at- 

 tached during the 

 process of imbibing food. 



(100.) The above examples will suffice to give the reader an idea of 

 the most ordinary provisions for obtaining nourishment met with 

 in the Pulmonigrada : we will therefore return to consider the 

 structure of the stomach itself, and of the canals which issue from 

 it, and convey the digested nutriment through the system. In 

 Cassiopea Borbonica, which will serve to exemplify the general 

 arrangement of these parts in the whole order, the stomach (Jig- 

 28) is a large cavity placed in the centre of the inferior surface of 

 the disc, and is apparently divided into four compartments by a 

 delicate cruciform membrane arising from its inner walls. Into 

 this receptacle all the materials 

 collected by the absorbing suck- 

 ers are conveyed through eight 

 large canals, and by the process of 

 digestion become reduced to a 

 yellowish pulpy matter, which is 

 almost fluid, and which is the 

 pabulum destined to nourish the 

 whole body. From the central 

 stomach sixteen large vessels 

 arise, (Jig. 29, c,) which ra- 

 diate towards the circumference 



