CLASSIFICATION. 37 



those of the Heliozoa ; and with one or more usually- 

 obscure nuclei. 



Genera: (11) Vampyretta, (12) Hyalodiscus, (13) 

 Nuclearia, (14) Archenna. 



Order II. CONCHULINA. 



(Testacea* Max Schultze.) 



Rhizopods furnished with a test, of variable shape 

 and construction. 



Family 1. ARCELLIDA. 



Test chitinous, with or without extraneous matter 

 adhering ; monothalamous ; nucleus single or multiple ; 

 contractile vacuoles one or several. 



Genera : (15) Arcella, (16) Pseudochlamys, (17) 

 Cenfropyxis, (1.8) Difflugia, (19) Pontigulasia, (20) 

 DifflugieUa, (21) Lecquereusia, (22) Nebela, (23) Hya- 

 losphenia, (24) Heleopera, (25) Quadrula, (26) Cochlio- 

 podium, (27) Leptochlamys, (28) Phryganella. 



Family 2. EUGLYPHINA. 



Test homogeneous, or composed of chitinous or 

 siliceous plates often of geometrical pattern ; spinous 

 or naked. Pseudopodia filose, sharply pointed, simple 

 or branched, but not anastomosing, of variable length, 

 emitted from the mouth of the test. 



Genera : (29) Euglijplia, (30) Placocista, (31) Assu- 

 lina, (32) Cyplwderia, (33) Trinema, (34) Corythion, 

 (35) Sphenoderia, (36) Campascus, (37) PampJiagus. 



Family 3. GEOMIINA. 



Test membranous, pellucid, rarely covered with ex- 

 traneous matter; with a single aperture. Pseudopodia 

 long, branching, straight, or irregularly dendroid, fre- 

 quently anastomosing. 



* Pre-occupied in Mollusca. 



