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University of California Publications in Zoology [VOL. 20 



The longitudinal axis and the longest transverse axis of each indi- 

 vidual were measured, and the ratio of length to breadth computed 

 (see Table I). 



TABLE I 



COMPARATIVE MEASUREMENTS OF 

 BALANTIDIUM COLI 



INDIVIDUALS FROM PIG No. 1 

 (Bal. suis, with five exceptions) 



ONE HUNDRED INDIVIDUALS EACH OF 

 AND BALANTIDIUM suis 



INDIVIDUALS FROM PIG No. 4 

 (Bal. coli, with one exception) 



* Other characters showed that these individuals were of the other species rep- 

 resented in the table. 



