The Sarcodina 207 



rM. 



T--.;»-: ■ y.V.*^-:--- 





B 











^J'-^'^'^-^x 











I F 





Fig. 5. 4. Actinophrydina: A. Actinosphaerium eichorni Ehrenberg (diam- 

 eter may reach or exceed SOOfi); axopodia, peripheral zone of vacuoles; in- 

 gested food (after Penard). B. Portion of peripheral cytoplasm, A. eichorni, 

 showing an axoneme ending in a granular layer just beneath the vacuolated 

 zone; diagrammatic (after Penard). C, D. Actinophrys pontica Valkanov; 

 stained specimen (C), xl200; fused aggregate of three organisms (D), x800 

 (after V.). E, F. Actinophrys sol Ehrenberg; stamed section of small specimen 

 showing axonemes extending to nucleus, x975; living specimen from culture, 

 x325 (after Belar). 



may exceed 1000/^ in diameter, is the largest of the Actinophrydina. Other species fall 

 within the range, 25-150/1. 



Suborder 2. Acanthocystidina. There is typically a secreted capsule, 

 sometimes "gelatinous" (Fig. 5. 5, A, G), in which skeletal elements are 

 embedded. The ectoplasm is not extensively vacuolated. In some genera at 

 least, the axonemes are known to end in a central granule. Data are 

 lacking in other cases, In Astrodiscuhis (Fig. 5. 5, A), the capsule is thick 



