,'350 APPENDIX. 



eight locomotive organs or bristles, representing 

 the eight legs of those animals. 1 By means of 

 these organs, this animal, which was found by 

 Dr. Ehrenberg in the Red Sea, performs a double 

 rotatory movement, one by the rotation of the 

 anterior pair, and the other by the three posterior 

 pairs. The motion of these filamentous legs is 

 so rapid that they appear as if, instead of eight, 

 a hundred were revolving, and so form a kind 

 of natural Phantasmascope. Another infusory 

 genus, Bacillaria, seems to prefigure the Salpes* 

 the species at first being concatenated in chains 

 or ribands, and afterwards separating. 3 The 

 animalcules forming this genus have sometimes 

 been mistaken for plants, and the quadrangular 

 form of the associated individuals gives them the 

 appearance of the jointed stem of a plant, rather 

 than of an animal chain. On a former occasion, 

 I alluded to other imitations of the vegetable 

 world exhibited by the polypes, particularly to 

 some of them producing seeming blossoms, con- 

 sisting, as it were, of many petals. 4 I shall now 

 notice some that represent monopetalous flowers. 

 A genus long known to naturalists, which seems 

 intermediate between the Infusories and the 

 Polypes, named originally by Linne Vorticella, 

 exactly simulates a bell flower with a spiral 

 footstalk. They are often found in fresh water, 



1 PLATE I. A. FIG. 6. 2 See above, p. 222. 



3 PLATE I. A. FIG. 4, />. * See above, p. 169. 



