264 



University of California Puhlications in Zoology [Vol. 



20 





or. pi. 

 dr. oes. f. 

 or. pi. f. 

 ad. oil. 



■ytpg- 



Fig. I. Balantidium ooli. Ventral view sliowing principal structures. The 

 adoral cUia, with exception of one at either side, are indicated by basal granules 

 only. The adoral membranelles are also represented solely by the basal apparatus. 

 Ectoplasm is shaded, and ciliary rootlets are shown on one side only. X 1250. 

 ad!, cil., adoral cilia; ad. cil. /., adoral eUiary fiber; ad. meinh., adoral membranelles; 

 ant. c. v., anterior eontractOe vacuole ; hg., basal granule ; hg. ad. cil., basal granules 

 of adoral cilia; cil., cilia; oil. r., ciliary rootlet; cir. oes. f., circumoesophageal fiber; 

 cytpg., cytopyge; ect., ectoplasm; enl. ad. cil.r., enlargement of adoral ciliary root- 

 let; end., endoplasm; gr. b., gianular band of ectoplasm; long, f., longitudinal 

 fibers; mao., niaeronucleus ; mic., micronucleus; mot., motorium; nuo. memb., 

 nuclear membrane; oes., oesophagus; or.pl.. oral plug; or. pi. f., oral plug fibers; 

 pel., peUicle ; per., margin of peristome ; post. o. v., posterior contractile vacuole ; 

 rad. /., radial fiber ; ret. v., rectal vacuole. 



