MASTIGOPHORA 29 



1. MoNOSlGA Kent. Small colorless forms, solitary and sessile, 

 attached directly or by a short stalk : 9 species ; in fresh and salt water. 



M. ovata Kent (Fig. 28). Individual ovate or spherical; length .08 

 mm. : in fresh and salt water. 



2. CoDONOSiGA Clark. Similar to Monosiga, but at the end of a 

 stalk and solitary or colonial: 1 species. 



C. botrjrtis Clark. From 1 to 20 individuals in a colony; length of 

 individual .08 mm., of stalk .014 mm. : in fresh and salt water. 



3. CoDONOCLADlUM Stein. Like Codonosiga, but the stalk branches, 

 each branch bearing an individual: 4 species; in fresh and salt water. 



C. umbellatum Stein. Number of branches 4 to 10, which some- 

 times also branch ; length .03 mm. : in fresh water. 



4. Salping(ECA Clark. Solitary; body enclosed in a shell, usually 

 cup-shaped, which is directly attached at base or at the end of a short 

 stalk: about 27 species; in fresh and salt water. 



5. steini Kent. Shell cylindrical; length .02 mm.: in fresh water. 



Order 4. EETEROMASTIGIDA. 



Two or more flagella present, one of which is directed forwards and 

 the others backwards, during locomotion; no shell present; animal 

 colorless: 2 families. 



Family BODONIDAE. 



Small, naked forms with 2 flagella of nearly equal length : 4 genera. 

 Key to the genera of Bodonidae here described: 



Ci Flagella spring from anterior end. 



hi Flagella longer than body, which is ovate 1. Bodo 



62 Flagella shorter than body, which is elongate 2. Piiyllomitus 



Oa Flagella spring from a lateral groove 3. Oxyrrhis 



Fig. 29 Fig. 30 Fig. 31 



Fig. 29 — Bodo caudatus (Calkins). Fig. 30 — PhyUomiius amylophagus (Conn). 

 Fig. 31 — Oxyrrhis marina (Calkins). 



1. Bodo Ehrenberg. Body more or less ovate, often amoeboid; 

 anterior end pointed, with 2 flagella arising from a slight depression: 10 

 species; in salt and fresh water. 



B. caudatus (Dujardin) (Fig. 29). Body ovate, often amoeboid; 

 flagella about the same length; length .018 mm. 



