PERITRICHA 



617 



Fig. 279. a, Astijlozoon fallax, X170 (Engelmann); b, Hastatella 

 aesculacantha, X580 (Jarocki); c, Opistho7iecta henneguyi, X500 

 (Lynch and Noble); d, e, Ophridium sessile (d, Xl.5; e, X65) (Kent); 

 f, 0. vernalis, X160 (Stokes); g, Scyphidia constrida, X360 (Stokes); 

 h, Paravorticella clymetiellae, X65 (Shuinway). 



thigmotactic bristles; pellicle smooth or furrowed; with or with- 

 out gelatinous envelope; in fresh water. A few species. 



A. fallax E. (Fig. 279, a). 70-100^; fresh water. 



Genus Hastatella Erlanger, Free-swimming; body surface with 

 2-4 rings of long conical ectoplasmic processes; fresh water. 



