CASSIOPEA BOKBONICA. 



107 



hang from the centre of the disk. Each of these appendages is found 

 to contain ramifying canals, opening at one extremity by numerous 

 minute apertures upon the external surface, whilst at the opposite they 

 are collected into four large trunks communicating with the stomach ; 

 as the Ehizostoma, therefore, floats upon the waves, its pendent and 

 root-like pedicle absorbs, by the numerous oscules upon its exterior, 

 such food as may be adapted to its nutrition, finding most probably an 

 ample provision in the microscopic creatures which so abundantly people 

 the waters of the ocean. The materials so absorbed are conveyed 

 through the canals in the interior of the arms into the stomachal cavity, 

 where their solution is effected. 



(274.) But it is not upon this humble prey that some of the MedusaB 

 feed ; many are enabled, in spite of their apparent helplessness, to seize 

 and devour animals that might seem to be far too strong and active to fall 

 victims to such assailants : Crustacea, worms, mollusca, and even small 

 fishes are not unfrequently destroyed by them. Incredible as this may 

 seem when we reflect upon the structure of these feeble beings, obser- 

 vation proves that they are fully competent to such enterprises. The 

 long tentacula or filaments with which some are provided, form fishing- 

 lines scarcely less formidable in arresting and entangling prey than 

 those of the Hydra ; and, in all probability, the stinging secretion which 

 exudes from the bodies of many species speedily paralyses and kills the 

 animals which fall in their way. The mouth of these Acalephas is a 

 simple aperture leading into the gastric cavity, and sometimes sur- 

 rounded with tentacula, that probably assist in introducing the food 

 into the stomach. 



(2 75 . ) In Cassiopea 



Borbonica, the principal Fig< **? 



agents in procuring nou- 

 rishment are numerous 

 retractile suckers (fig. 50, 

 a), terminating in small 

 violet - coloured disks, 

 which are dispersed over 

 the fleshy appendages to 

 the under surface of the 

 body ; the stem of each of 

 these suckers is tubular, 

 and conveys into the sto- 

 mach nutritive materials 

 absorbed from animal 

 substances to which they 

 are attached during the 

 process of imbibing food. 



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



Cassiopea Borbonica. 



