74 NATURAL HISTORY 



zation to be nearly allied to the Trichoda anas, to which 

 the reader is referred. The mouth, which is a longitu- 

 dinal opening, situated in the neck, is devoid of ciliae. 

 The polygastric structure of its digestive organ is readily 

 demonstrated : it propagates by division, and just before 

 its separation has a very singular appearance in swim- 

 ming, which is always rapid, Length, 1 -300th of an 

 inch. 



115. Y iBRio olor {LacrT/maria olor, E.) Thesivan Vi- 

 hrio, — This is a very diverting little animalcule; its quick 

 and lively movements among the confer vae which it in- 

 habits, and the rapidity with which it is continually 

 changing its form, contracting and expanding its long 

 neck, combine to give it an interest not equalled by any 

 of the larger animals. It seldom removes far from the 

 vegetation on which it is found, and is constantly in the 

 search of prey, moving its head with great rapidity, and 

 inflecting the neck into various forms. The magnified 

 views, figures 52 and 53, shew it contracted and ex- 

 tended : in the latter condition I have observed them 

 l-80th of an inch long. They are found among confervas 

 and in green stagnant water. 



116. Vibrio ci/gnus. The cygnet Vibrio, — ^This ani- 

 malcule is smaller than the preceding; the neck is 

 shorter ; the extremity not dilated ; and its posterior end 

 is more slender. I am inclined to think it is only the 

 infant state of some other species. It is sluggish in its 

 movement. Found in stagnant water. 



117. Vibrio awser {Amphileptus anser, E.) The goose 



