PAMPHAGU6. 31 



Shell retort-shaped, but fundus with a pair of PAOK. 



divergent processes, Campascus, 34 



Shell ovoid, hyaline, of regular rows of oval or 

 hexagonal chitinoid plates, mouth serrulate ; 

 shell usually with spines or hairs, Euglypha, 35 



Shell compressed oval, colorless, mouth ellip- 

 tical, with border entire and acute com- 

 missures, Placocista, 38 



Shell compressed spherical or oval, mouth with 



ragged edges, Assulina, 39 



Shell hyaline, pouch-like, sometimes composed 

 of circular plates, long axis inclined, mouth 

 subterminal, Trtnema, 39 



Shell globular or oval, hyaline, short, broad 



neck, and subterminal or oblique mouth, Sphenoderia, 40 



DESCRIPTION OF GENERA AND SPECIES. 



GENUS I. PAJMPHAGUS. 



SYN. : Arcella, Homaochlamys, Ehr. ; Gromia, Schlumberger; Cory- 

 cie, Duj.; Difflugia, Schneider ; Pamphagus, Bailey, C. and L., Plagio- 

 phrys, Lecytketim, H. and L. 



Animal colorless, transparent, invested with a hyaline, 

 structureless membrane, which is flexible and elastic, and 

 concurs strictly with any changes of form of the body, 

 but ordinarily restricts such changes and is not voluntarily 

 extensible ; sarcode completely filling it, and appearing 

 to be structurally continuous with it. Nucleus large and 

 clear. Contractile vesicles not distinctly determined. 

 Mouth small, terminal. Pseudopods filamentous, long, 

 exceedingly delicate, branching dichotomously, not anasto- 

 mosing. 



