Bull. U S. F. C. 1893. On a Parasitic Protozoan. (To face page 182 



Plate 12. 



Jchthyophthirivis multifiliis {showing ectoplasma, endoplasma, 

 granules, pigment, contractile vacuoles, nucleus, mouth, and 



cilia 



* The same; the animal has changed its orientation so that the 



., a m °uth 1S turned towards the observer. 



.^.""diagrammatic figures of the division. The cyst appears 

 in the 10-cell stage (beginning of the 10-cell stage). 



3. One-cell stage, seen at 1 o'clock p. m. 



4. Two-cell stage, at 1:45 p. m. 



5. Four-cell stage, 3:15 p. m. 



6. Eight-cell stage, 4 p. m. 



7. Sixteen-cell stage, 5 p. m. ; the membrane is present. 



8. Thirty-four-cell stage, formed at 7:30; membrane broke at 8:c0. 



9. One of the ciliates encysted in its 2-cell stage. 



