ARTHROPOD A. 



285 



Fia. 253. Barnacles, or Pedunculate Cirripedes (Lepas anatifera). 



united to this class, but now are known to be widely re- 

 moved from it. The former is by some authors removed 

 from the Crustacea. 



3. Tetradecapods, small, fourteen-footed species ; as the 



FIG. 254. Acorn-shells (Balanus) on 

 the Shell of a Whelk (Buccinum). 



FIG. 255. Water-fleas : 1, Cyclops communis, 

 2. Cypris uni/aaciata; 3, Daphnia pulex. 



