INFUSORIA. 417 



surface in crawling affords a pleasing siglit : particularly 

 when the animal is running back-downwards on the upper 

 glass plate of the live-box. Some species have bristles 

 (or setcp) affixed to the hinder part of the shell, from which 

 they diverge. In E. truncatus these are four ; but they 

 are wanting in E. charon. The body displays a mass of 

 granules, vacuoles, and vesicles of different sizes. 



These are very beautiful objects ; and their sprightly 

 motions and apparent intelligence give them an additional 

 interest. They crawl more than they swim, running with 

 great swiftness hither and thither, frequently taking short 

 start?, and suddenly stopping. The specimens which we 

 are examining are taken from w T ater which had been kept 

 in a jar for several weeks. The vegetable matters are 

 decaying; and among the stems and filaments this pretty 

 species crawls and dodges about. It seems reluctant to 

 leave the shelter of the decaying solution; sometimes one 

 will creep out a little way into the open water, but in 

 an instant it darts back, and settles in among the stems 

 and flocculent matter. Any attempt by turning the glass 

 cover to bring it out into view only makes it dive deeper 

 into the mass, as if seeking concealment. This is about 

 TT—y of an inch in length of lorica ; and the E. charon 

 is not more than one-fourth of this size. These creatures 

 remind one of an Oniscits, especially when in profile. 



There is an animal very closely allied to these, but 

 much more beautiful, being of a clear greenish trans- 

 lucency, with several vesicles filled with a rose-coloured 

 or purple flu.d of much brilliancy. This creature, which 

 bears the name of Chlamidodon, has the peculiarity of a 

 set of wand-like teeth arranged in a hollow cylinder. 



And with these we dismiss the Infusoria, a class of 

 animals which, from their minuteness, the number and 

 variety of their species, their exceeding abundance, the 

 readiness with which they may be procured, and, as it 

 were, made to our hand (by simply steeping vegetable 



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