OMNIVOROUS ANNELIDS, &c. 263 



All wheel-animalcules, however, are not entirely limited, as 

 regards food -supply, to what is brought by ciliary currents. 

 Some of them (fig. 470), such as the beautiful Crown Rotifer 

 (Stephanoceros), possess a number of pointed projections from 

 the head - region, which are actively used to surround small 

 animals or other food substances, and their efficiency may be 

 increased by the presence of slender bristles, as in the Flower 

 Rotifer {Floscularid). The mouth of a wheel -animalcule leads 

 into a funnel-shaped pharynx lined with cilia, and this again is 

 continuous with a powerful muscular gizzard (mastax) imbedded 

 in the walls of which are hard jaw-like pieces used for chewing. 

 In many cases these jaws can be protruded from the mouth and 

 employed for seizing food, even, it may be, for attacking other 

 rotifers with a view of adding them to the bill of fare. 



