20 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Larger animals, commonly with one large flagellum, 

 sometimes with two such flagella, or with a single 

 large flagellum and a secondary one. Mouth and 

 commonly a pharynx at the base of the flagel- 

 lum EUGLENOIDINA, p. 24 



With two or more equal flagella 



ISOMASTIGODA, p. 32 

 SUB-ORDER MONADINA. 



Key to Genera. 



1. Possessing both flagella and pseudopodia ; readily 



passing into a Heliozoid stage 2 



Commonly without pseudopodia; with one flagellum 3 

 Without pseudopodia ; with one flagellum, and one 



or two secondary flagella 8 



2. One evident flagellum and lobe-like or pointed pseu- 



dopodia Mastigamoeba* 



In flagellate stage, with one or two flagella ; in Helio- 

 zoid stage, without flagella Ciliophrys 



Two flagella in both stages ; pseudopodia simple, with 



axis fiber Dimorpha 



Two flagella in both stages ; pseudopodia various, 

 without axis fiber Cercohodo* 



3. Without lorica 4 



With lorica 6 



4. Posterior end elongated into a tail ; sometimes amoe- 



boid Cercomonas* 



No tail, although sometimes narrowed posteriorly; 



free or attached ; flagellum vibratile Oikomonas* 



Body ovate, flattened, free; flagellum usually carried 

 obliquely forward and vibratile only at its end . . . 



Notosolenus* 



6. Solitary 7 



Colonial ; daughter-individuals attached to inner wall 



of lorica Poteriodcndron 



7. With a peristome process Bicosoeca 



Without a peristome process Codonosca 



8. Without chromatophores 9 



With yellow to brown chromatophores 13 



