TEE CCELENTERATES 137 



When strolling on flat, sandy beaches, especially in the spring 

 and early summer, we commonly see what appear to be little balls 

 of exceedingly transparent and glassy jelly, no larger than an 

 ordinary marble. If picked up and examined, we observe that 

 they are not quite spherical, but oval in form, with a little tubercle 

 at one end, and eight equidistant bands running from this to the 

 opposite end, like the meridians on a globe. 



This extremely beautiful little creature is one of the ccelenterates, 

 belonging to the division Ctenophora, or comb-bearing jelly-fishes, 

 so called because they possess comb-like ciliated plates, and is 

 called the Globular Beroe (Cydippe pileus}. 



The ctenophores are very active creatures, swimming freely in 

 the open seas by means of their numerous cilia ; and, although of 

 such delicate structure, are very predaceous, devouring small 

 crustaceans and other marine animals. They are usually globular 

 in form, but some are like long ribbons, and almost all are remark- 



FIG. 89. Cydippe pileus 



able for their wonderful transparency, which renders them nearly 

 invisible when floating in water. They have not the power of 

 stinging or paralysing their prey, as the medusae have, but their 

 fringed arms are provided with adhesive cells by which they hold 

 their prey tenaciously. 



In order to observe the form and habits of the Beroe we 

 transfer it to a vessel of sea water, when it immediately displays 

 its regular spheroid form, and its eight rows of comb-like plates 

 which form the meridians before alluded to. Its mouth is situated 

 on the little tubercle at what we may call the lower pole, for it is 

 the habit of the Beroe to swim in an inverted position, and the 

 digestive cavity may be seen through its glassy body. 



At first no appendages of any kind are visible, but soon the 

 animal protrudes two long and exceedingly slender arms, fringed 

 with slender gelatinous threads, from two cavities, at opposite 

 sides of the body, into which they can be withdrawn. A close 



