306 



ROTIFERA. 



(Melicerta, Fig. 247). A small number are parasitic. Many of 

 them possess to a remarkable degree the property of resisting the 

 effects of drought and a high temperature (200 F.). This power 

 is particularly developed in the Bdelloidea. On the approach of the 

 adverse influence they protect themselves by a gelatinous secretion 



FIG. 248. Jaws of RoUfera.l, Malleate ; 3, Sub-malleate ; 3, Forcipate ; 4, Incudate ; 

 5, Malleo-ramate ; 6, Uncinate ; 7, Ramate (from Hudson and Gosse). ms malleus ; 

 is incus ; rs rami ; fin fulcrum ; mm manubrium ; us uncus. 



which protects them against evaporation. The duration of life is 

 often very short. The female of Hydatina senta attains maturity 

 in three days and lives only fourteen days; and the males live 

 only three days. 



The position of the Rotifera in the system is obscure. Apparently 



