NOTES ON SOME CANADIAN INFUSORIA. 307 



versely wrinkled on the concave border. These points, however, do 

 not appear to be of sufficient moment to authorize the establishment 

 of a new species. 



A peculiar feature in the ingestion of food was noticeable, which 

 1 have observed in no other form. Below the termination of the 

 pharynx was a clear spot (y), which appeared to be ciliated on first 

 looking at it, but the ciliation on further examination was seen to 

 belong to certain structures contained therein. On watching it, it 

 was seen to detach itself after a time from the pharynx and pass 

 down the left side of the body close underneath the cuticle, the cilia 

 continuing to work until it reached that point where the body com- 

 mences to taper off" into the foot, where it stopped and gradually disap- 

 peared. In the meantime a new spot has appeared at the termination 

 of the pharynx, and it in its turn passes through the same changes. 

 I believe the explanation of this phenomenon is to be found in the 

 • manner of feeding. The clear spot is merely an enormous food 

 vacuole, the animal not absorbing its food into the protoplasm of the 

 body, until a considerable quantity of it has been collected, and the 

 apparent ciliation of the vacuole, as stated above, is due to the pres- 

 ence of ciliated forms in its interior. The appearance and disap- 

 pearance of the vacuole is apparently rhythmical, but this was due to 

 the animalcule being in a situation to obtain a large and constant 

 supply of nutrition, but even then the intervals between the swallow- 

 ing of the vacuoles varied considerably. 



Gyclidium glaucoma, eherh and margaritaceum. 



These two forms occurred in considerable abundance, particularly 

 the former, which, however, seemed to be rather susceptible to cold, 

 while the latter was not affected. G. glaucoma (fig. 3) measures 

 about 0.019 mm., and is covered throughout with bristle-like cilia, 

 which, however, are capable of very powerful action. At the 

 posterior extremity of the body (and not the anterior as has been 

 stated) is the contractile vesicle (c. v.), and behind it an extremely 

 long seta. The mouth is situated on the under surface of the body, 

 and is provided with an exceedingly large hood-shaped retractile 

 structure (h). These forms collect in large numbers wherever the 

 light shines most strongly. Their motion is exceedingly rapid and 

 jerky ; usually remaining at rest, when disturbed one after the 

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