38 



SYSTEMATIC ZOOLOGY 



secrete a chitinous, flask- or vase-shaped shell about themselves, 

 through the opening of which the body may be protruded. 

 Those containing chlorophyll granules often have a cell wall of 



B 



c.vztc 



A-D, various shapes assumed during locomotion; E. a si 

 individual more highly magnified; F, the anterior end of the body Mill further enlarged; 

 <1. two individuals in a cyst, c.vac, contractile vacuole; cy, cyst; ft, flagellum ; m, mouth; 

 jiii, nucleus; a >. oesophagus; pg, pigment spot. (Alter Kent and Klebs, from Parker and 

 Haswell's Manual. | 



cellulose. Iii main - eases there is no definite mouth ; this is 

 true of some of the naked species, where the food consists 

 purely of nutritive fluids, which are absorbed directly into the 



I.Dinobryon 2.Syncrybta 3 Anfhofjhysa 4.Rhi|>idodendron 



Fio. 19. Variously shaped colonies of Flagellata. (From Parker and Haswell's 



Manual.) 



protoplasm, and also of those which are colored and inclosed 

 in a continuous membrane of cellulose; here the nutriment is 

 obtained from the water and assimilated precisely as in the case 

 of plants. But often there is a definite mouth situated at the 



