Phylum Protoplasta [ 205 



karyogamy, and meiosis to occur at this point; the chromosome number (n) is 7. The 

 disk changes into a column which bends, and then falls, toward the light, and after- 

 ward creeps some distance in the same direction. When this has happened, the fore- 

 most cells, being those which were originally in the middle of the disk-shaped mass, 

 pile up again to form a sterile stalk perhaps one millimeter tall; the cells behind them 

 crawl up the stalk to form the globular mass of spores; the hindmost, being those 

 which were last to arrive at the disk-shaped mass, remain behind to form a flange 

 about the base of the stalk. 



Order 2. Lampramoebae Haeckel Gen. Morph. 2: xxiv (1866). 

 Order Testacea Schultze 1854, non L. (1758). 

 Order Thecamoebae Haeckel. 



Order Conchulina Cash and Hopkinson British Freshw. Rhizop. 1: 37 (1905). 

 Suborder Testaceolobosa de Saedeleer in Mem. Mus. Roy. Hist. Nat. Belgique 



60: 5 (1934). 

 Order Testacida Hall Protozoology 241 (1953). 



Order Testaceolobosa Deflandre in Grasse Traite Zool. 1, fasc. 2: 97 (1953). 

 Amoeboid organisms without known flagellate stages, bearing shells and producing 

 lobopodia. Various organisms producing rhizopodia or filopodia, traditionally asso- 

 ciated with these, have here been placed among Rhizopoda or Heliozoa, as suggested 

 by de Saedeleer (1934) and Grasse (1953). Deflandre (in Grasse, op. cit.) distin- 

 guishes several families beside the following: 

 1. Shell without secreted scales of silica. 



2. Shell of uniform secreted material Family 1. Arcellina. 



2. Shell with imbedded grains of sand Family 2. Difflugiida. 



1. Shell with secreted scales of silica Family 3. NEBELroA. 



Family 1. Arcellina Ehrenberg Infusionsthierchen 129 (1838). Family Arcellidae 

 Schultze 1876. Arcella, etc. 



Family 2. Difflugiida [Difflugiidae] Taranek 1881. Difflugia, etc. 

 Family 3. Nebelida [Nebelidae] Schouteden 1906. Nebela, the shell beset with 

 circular siliceous scales; Quadrula, the scales square; etc. 



