IO6 THE PROTOZOA 



Frenzel ('92), lagoons; Gloidium Sorokin ('78). fresh water; Chcetoproteus, 

 (Dinamceba Leidy) Stein ('57), fresh water; Trichosphcerittm Schneider; 

 Pachymyxa Gruber; Hyalodiscus Hertwig and Lesser ('74), fresh water.; 

 Plakopus F. E. Schultze (75), fresh water; Dactylosphara Hert. & Less. (74), 

 fresh water: Chroinatella Frenzel ('92), fresh water; Stylamceba Frenzel ('92), 

 fresh water; Saltonella Frenzel ("92), fresh water; Eikenia Frenzel ('92), fresh 

 water; Pelomyxa GreefF ('74), fresh water; Amphizonella Greeff ('66), fresh 

 water; Podostoma Clap. & Lach. ('58), fresh water; Arcnothrix Hallez ('85), 

 cultures of Ascaris megalocephala. 



Suborder 2. THECAMCEBINA. Amrebida provided with a shell, with lobose 

 pseudopodia, which may be sharp pointed and branched, and with one or more 

 nuclei and contractile vacuoles. 



Family 2. Arcellidae. The shell is more or less membranous. Contractile vacuoles 

 are numerous; the nucleus is single or multiple. Genera: Arcella Ehbg. ('38), 

 fresh water, common ; Cochliopodium Hert. & Less. ('74), fresh water, common ; 

 Pyzidicida Ehbg. ('38), fresh water; Pseiidochlamys Clap. & Lach. ('58), fresh 

 water; Hyalosphenia Stein ('57). fresh water; Qitadrula F. E. Schultze (75), 

 fresh water; Difflugia Leclerc ('15), fresh water, common; Lecquereusia 

 Schlumberger, fresh water. 



Family 3. Euglyphidae. The shell is formed of regular plates of chitin, or of silica, 

 and is often provided with spines. The pseudopodia are sharp pointed and 

 often branching, but do not anastomose. Genera: Euglypha Dujardin ('41), 

 fresh water; Trinema Duj. ('36), fresh water; Cyphoderia Schlumberger ('45), 

 marine and fresh water; Campascus Leidy (77), fresh water; Nadinella 

 Penard ('99). 



Order 2. RETICDLARIIDA. Rhizopoda with fine branching and anastomosing, or 

 reticulate pseudopodia, forming an irregular network around the body, which 

 may or may not have a shell. Shells, when present, are calcareous (rarely 

 silicious) and provided with many pores (Perforina), or without pores (Imper- 

 forina), and consisting of one chamber (Monothalamous), or of many chambers 

 (Polythalamous). 



Suborder i. NUDA. Shell absent; the pseudopodia are reticulate, and the cell- 

 body, in many cases, is apparently without a nucleus ; marine. Genera : 

 Gymnophrys Cienkowski ('76) ; Protamyxa Haeckel ('68) ; Myxodictyum 

 Haeckel ('68); Protogenes Haeckel ('64) ; Pontomyxa Topsent ('93). 



Suborder 2. IMPERFORINA. [With but few modifications, the following classifica- 

 tion of the Reticulariida is taken from Brady ('84) and Lankester ('85), after 

 Carpenter ('69)]. Shell-bearing forms; the shells are calcareous, solid, and 

 without minute apertures, or they are made up of foreign particles cemented upon 

 a chitinous base. They may have one, two, or many mouth openings, and are 

 either monothalamous or polythalamous. 



Family i. Gromidae. The shell is membranous and in the form of a simple sac, 

 with a pseudopodial aperture either at one extremity or at each end. The 

 pseudopodia are long, branching, and anastomosing ; marine and fresh-water 

 fqrms. 



Subfamily i. Monostomince. The shell has but one aperture. Genera: Gromia 

 Duj. ('35); Lieberkuhnia Clap. & Lach. ('58). both found in fresh water, the 

 former also marine ; Microgromia R. Hertwig ('74), fresh water : Platoutn F. E. 

 Schultze ('75); Plectophrys Entz ('77); Pseiidodifflugia Schlumberger ('45), 

 brackish and fresh water. 



Subfamily 2. Amphistotnince. With an aperture at each end of the shell. Genera : 

 Diplophrys Barker ; Ditrema Archer (70) ; Amphitrema Archer ('70) ; Shep- 

 heardella Siddall ('80). 



