Mastigophora 



55 



2 — One or several flagella, mostly directed forward 3 



— Usually 2 flagella, one directed forward, the other backwards Heteromastigoda 



3 — Mostly small species, with one large flagellum and one or more smaller secondary 

 flagella. Colonial species, Dinobryon (fig. 5) ; Uroglena (fig. 9) ; solitary, with a shell 



of plates bearing spines (fig. 12) Mallomonas 



— Larger species, with one large flagellum (sometimes 2), mouth at base of flagellum. .4 

 — With 2 or more equal flagella 6 



(Continued on page 56) 



Plate 22. Flagellates 



