The Sarcodina 239 



may, as "main pseudopodia," become large enough to include the whole 

 organism and thus direct locomotion. And there are also certain amoebae 

 which develop no typical pseudopodia at all during locomotion. Such is 

 the case in Trichamoeba and Thecamoeba, in which locomotion is best 

 characterized as protoplasmic flow. The eventual correlation of such 

 characteristics with adequate cytological data should furnish a much 

 clearer picture of generic boundaries and relationships than is now 

 available for the free-living amoebae. 



Some of the genera which have been proposed for various types of Amoebidae are 

 listed below; certain others have been characterized by Schaeffer (132). 



Acanthamoeba \'olkonsky (50, 150; Fig. 5. 25, M-O); Amoeba Ehrenberg (Fig. 5. 26, 



Fig. 5. 27. A. Flabelhda mira Schaeffer (marine), in locomotion; xl740 

 approx. (after S.). B. Dinamoeba mirabilis Leidy, characteristic spine-like 

 pseudopodia; some specimens show adherent rods, possibly bacteria; xl25 

 (after L.). C. Thecamoeba orbis Schaeffer, in locomotion, showing typical 

 ectoplasmic ridges; xl600 (after S.). D. Hartmanella kUtzkei Arndt, many 

 ingested bacteria, stained preparation; xl250 approx. (after A.). E. Pelo- 

 myxa ("gray type," P. palustris), longitudinal section of slug-like body 

 showing many nuclei, several food vacuoles, central axis, and tail-piece 

 ("telspn") of hyaline cytoplasm; x53 approx. (after Okada). 



