SOIL PROTOZOA 331 



A. SARCODINA* 3 



I. Actinopoda, pseudopodia with axial filaments. 



Heliozoa, spherical, with fine radiating pseudopodia, with stiff axial 

 rods; endoplasm surrounded by vacuolated ectoplasm. The fol- 

 lowing representatives of this group have been found in the soil: 

 Actinophrys sol (F, I, K, J), Raphidiophrys (F), Acanthocystis 

 aculeata (I), Clathrulina elegans (F). 

 II. Rhizopoda, pseudopodia without axial filaments. 



1. Proteomyxa, pseudopodia fine and radiating, often anas- 



tomising or forming a net-work. Among the soil forms be- 

 longing to this group are Biomyxa vagans (J), Nuclearia 

 simplex (A, I, J, L, M), Gephyramoeba delicatula (C and J), 

 Leplomyxa reticulata and L. flabellala(c), Vampyrella lat- 

 erita (F). 



2. Amoeboea, naked or with chitinous shells (tests). 



(a) Amoebida, naked rhizopoda, without any shells or sup- 

 porting structures; pseudopodia blunt or pointed but 

 never filamentous; may be reduced to wave-like ex- 

 pansions of protoplasm. 



(a') Amoeba Umax group. Small amoebae with single 

 rounded pseudopodium; sometimes several 

 finger-like pseudopodia formed simultaneously. 

 Naegleria gruberi, one of most common soil pro- 

 tozoa recorded by Wilson, F and G. Hart- 

 manella hyalina is also very abundant in the 

 soil. Amoeba (Hyalodiscus) gutulla was found 

 by A, B, F, I, J and K. 

 (b') A. verrucosa group. Pseudopodia in the form of 

 ridges or folds of the ectoplasmal pellicle. 

 A. verrucosa (A. terricola?) was found in the soil 

 by A, B, C, I, J, K and N. A. diploidea by D 

 and J, A. striata by B and J. 

 (c') A. lamellipodia group, similar to previous group, 

 with less strongly developed pellicle, including: 

 A. glebae (J), A. actinophora (J), A. goban- 

 niensis (D). 

 (d') A. proleus group. Large amoebae, changeable in 

 shape, with numerous long, cylindrical pseudo- 



83 For the identification of this group, consult, in addition to the general 

 treatises and papers, also Edmondson, C. H. Amoeboid protozoa (Sarcodinia), 

 in Ward and Whipple's Fresh-water biology. 1918, p. 210; Leidy, J. Fresh 

 water rhizopods of North America, U. S. Geol. Surg., 12: 324. 1879; Cash, J., 

 and Wailes, C. H. The British freshwater rhizopoda and heliozoa. Vols. 1-5, 

 1905-1921. Roy. Soc. London; Penard, E. La faune rhizopodique du bassin 

 de Leman. Geneve. 1902; Poche, F. Arch. Protistenk., 30: 251-310. 1913; 

 Ghosh, E. A new general classification of protozoa. Jour. Roy. Micr. Soc, 

 272: 327-329. 1925; Sandon, 1927 (p. 329). 



