20 PROTOZOA 



Division 2. IMPERFORINA. 



Rhizopods with shell which has one or more large openings from 

 which project reticulate and anastomosing pseudopodia; shell usually 

 calcareous, but sometimes membranous, to which sand may adhere, and 

 one or many chambered: 4 families. 



Family GEOMIIDAE. 



Marine and fresh-water rhizopods with a membranous shell with 



an opening at one or both ends : 10 genera. 



Key to the genera of Gromiidae here described: 



Oi Shell with but one opening. 

 h^ Pseudopodia richly anastomosing ; contractile vacuoles usually present. 



1. Gromia 

 &2 Pseudopodia anastomosing little ; numerous contractile vacuoles. 



2. Pampiiagus 

 Ca Shell with an opening at each end 3. Diplophrys 



I / 



^•. Vs!t:^ ... 









Fig. 15 — Gromia lagenoides (Calkins). 



1. Gromia Dujardin. Shell spherical or ovate in shape and entirely 

 filled by the protoplasmic body; shell membranous and often flexible, 

 changing its shape; pseudopodia very fine and reticulate; nuclei one or 

 many: several species; in fresh and salt Avater. 



G. lagenoides Gruber (Fig. 15). Body about .25 mm. long, with 

 opening at larger end of shell; edge of opening turned in; a fine layer 

 of pi'otoplasm surrounds the shell which has fine reticulate pseudopodia 

 on all sides of it; shell either with or without foreign bodies: Woods 

 Hole; not numerous. 



2. Pamphagus Bailey. Pseudopodia very delicate, springing from 

 a common protoplasmic base and not anastomosing; shell flexible and 

 delicate, and filled by the protoplasmic body; opening of shell narrow: 

 7 species. 



