100 



THE VALKERIA IMBRICATA. 



orifice of its tubular cell, the polyp spreads out ten 

 long slender arms surrounding the mouth. On 

 their outer surface is a row of stiff spines ; and 

 besides these, a number of minute vibrating cilia, 

 which are thrown continually into the most rapid 

 movements, so as to produce a vortex, a mimic 

 whirlpool, gyrating to the mouth, and carrying with 

 it particles of food. Sometimes the arms themselves 

 grasp minute objects, and 

 draw them in. The mouth 

 surrounded by the arms, a, is 

 a simple orifice leading into a 

 capacious gullet, b : this gra- 

 dually narrowing, terminates 

 in a muscular gizzard, c, of a 

 rounded figure, with fibres 

 radiating from two dark spots, 

 and internally furnished with 

 minute bruising teeth. To 

 this succeeds a stomach, d, 

 apparently furnished with nu- 

 merous glands. 



POLYP AND CELL OE VAL- ^ intestinal Q ^l, 6, 



KERIA IMBRICATA, (im- 



maturo.)!. Horny base, emerges from the upper por- 

 2. Soft part of tube, tion of the stomach, and run- 

 3 Bristles, supporting a , . 



filmy transparent web. nm g upwards, terminates below 



the base of the arms. When 



the animal withdraws into its cell, by the aid of certain 



muscles, the alimentary canal is thrown into tortuous 



folds. Two of these retractor muscles may be seen, 



