The Mastigophora 121 



some cases the inorganic elements apparently are adherent to the "shell- 

 membrane"; in others, they are embedded in the membrane (46, 186). 



Chromatophores (Fig. 4. 1, B-J) range from the network of Chrysapsis 

 fenestrata to a broad plate or a narrow ribbon. In addition to the usual 

 colors — golden-yellow to greenish-brown or brown — blue chromatophores 

 have been reported (173). Pigments include chlorophyll a, lutein (a 

 xanthophyll) and ^-carotene. Supposed pyrenoids have been noted in 

 some species but not in many others. A stigma may or may not be present 

 in chlorophyll-bearing forms. Species within a genus, such as Chromulina, 



Fig. 4. 3. A-D. Ochromonas granulans (after Doflein). A. Specimen with 

 three food vacuoles, chromatophore, leucosin; xl650. B. Temporarilv at- 

 tached form just after ingestion of food; x2100. C. An amoeboid form just 

 after ingesting a bacillus; x2025. D. Nucleo-flagellar connections; x2100. E, F. 

 Monas vestita, during and after ingestion of food; note stigma and outer layer 

 of "mucus" with radiating strands; xl800 approx. (after Reynolds). G. Oiko- 

 monas termo (Ehrbg.) Kent, ingestion of a bacterium just completed; xl600 

 (after Lemmermann). 



