500 



PROTOZOOLOGY 



•i/w a 





& 



b ^ |V c 



«^6 ft c, toc 



Fig. 211. Diagram illustrating the life-cycle of Peneroplis pertusus 

 (Winter), a-f, megalospheric generation; g, gamete formation; h-k, 

 isogamy; 1-n, microspheric generation; o, multiple division. 



Genus Alveolinella Douville (Fig. 210, w) 



Test globular, aperture small, not toothed; recent only 



Family 23 Keramosphaeridae 



Genus Keramosphaera Brady 



Test calcareous, perforate 



Test vitreous with a glassy lustre, aperture typically radiate, not 

 trochoid 



