172 The Mastigophora 



Fig. 4. 39. A-F. Uistomonas nieleagridis Tyzzer: A. Rounded stage showing 

 nucleo-flagellar connections, x2310 (after Bishop). B. Specimen with four flagella 

 and rhizostyle, xl866 (after Wenrich). C. Daughter nuclei joined by paradesmose, 

 x2310 (after Bishop). D. Uniflagellate form with rhizostyle, x2310 (after Bishop). 

 E. Ingestion of food by means of a "tube," xl866 (after Wenrich). F. Elongated 

 imiflagellate form, x2310 (after Bishop). G. Rhizomast/x gracilis Alexeieff, nu- 

 cleus and rhizostyle stained; x2000 (after Mackinnon). H. Cyst of R. gracilis, 

 two nuclei and two rhizostyles; x2000 (after Mackinnon). I. Heliohndo radians 

 Wilkanov; x2400 (after V.). J, K. Mastigina hylae (Frenzel) Goldschmidt (after 

 Becker); specimen showing nucleus, flagellum, rhizostyle extending posteriorly, 

 and cap-like "cape" fitting over nucleus anteriorly (J), x515; pattern of proto- 

 plasmic streaming (K), diagrammatic. L. Mastigella polyniastix Frenzel, x400 

 (after F.). 



Species of Mastigatnoeba and Mastigella are similar with respect to the 

 single flagellum and the development ot slender pseudopodia. However, 

 the nucleus is approximately central and not connected with the flag- 

 ellum in Mastigella, while the nucleus in Mastigamoeha is anterior and 



