70 



PROTOZOOLOGY 



with a postoral depression; peristome closer to mid-ventral line; 

 fresh or salt water. Several species. 



C. phoenix Penard (Fig. 327, i). 35-50^ long; fresh water. 



C. media Kahl (Fig. 327, j). 45-50m long; in salt water. 



Genus Ctedoctema Stokes. Similar to Cyclidium in body form; 

 peristome nearer median line, diagonally right to left; right peri- 



Wto> A 



Fig. 328. a, Ctedoctema acanthocrypta, X840 (Kahl); b, Calyptotricha 

 pleuronemoides, X180 (Kahl); c, Histiobalantium natans, X420 (Kahl); 

 d, H. semisetatum, X270 (Noland); e, Pleurocoptes hydr actiniae, X470 

 (Wallengren); f, Cohnilembus fusifor?nis, X560 (Kahl); g, C. caeci, X390 

 (Powers); h, Philaster digitifomris, X220 (Kahl); i, P. armata, X240 

 (Kahl); j, Helicostoma buddenbrocki, X190 (Kahl). 



stomal ridge with a sail-like membrane which surrounds the cyto- 

 stome at its posterior end; trichocysts throughout; fresh water. 



C. acanthocrypta S. (Fig. 328, a). Ovoid; anterior end truncate; 

 macro nucleus round, anterior; about 35ju long; in fresh water among 

 vegetation. 



Genus Calyptotricha Phillips. Somewhat resembles Pleuronema or 

 Cyclidium; but dwelling in a lorica which is opened at both ends; 

 with zoochlorellae; fresh water. 



C. pleuronemoides P. (Fig. 328, b). Lorica about 85/* high; body 



