x ii LIST OF ILLUSTRATIONS. 



PAGE 



SECTION OP SPONGE 386 



THREK-SIDED EUGLENA * 



SWAN-NECK AND ITS DIVISIONS 394 



PARAMtECIUM 398 



COLEPS AND CHILOMONAS 3 " 



VORTICELLJS 402 



ACINETA 4 ' 



VAGINICOLA ^ 



EUPLOTES 416 



