44 THOUGHTS ON ANIMALCULES. 



positions, (pi. n, figs. 14, 15). This animalcule often 

 occurs in immense numbers, appearing like a crust of 

 jelly on the stems and twigs in the water, (see pi. u, 

 fig. 16). 



The BLUE STENTOR (pi. n, fig. 13) has a longitudinal 

 crest, or ridge, extending down the side of the body, 

 (pi. n, fig. 13 a). 



II. The BELL-SHAPED ANIMALCULES, or Vorticella, (pi. 

 m). These are the most common, and at the same time 

 the most elegant, of the Polygastria. They are met with 

 in clusters of myriads, attached to leaves, twigs, roots, 

 or other bodies in the water. They quickly appear in 

 vegetable infusions; and the transparent mucus ob- 

 servable on aquatic plants, and in vessels containing 

 infusions, will generally be found to consist of some 

 species of this genus. They are often attached in 

 clusters to the shells of the small Crustaceans (Mon- 

 oculus, Cyclops, &c.) that abound in the water. The 

 common Water-Flea is frequently infested with them, and 

 may be seen swimming about \\ ith groups of Vorticellas 

 affixed to its case. 



The body of these elegant creatures, (pi HI, fig. 3), is 

 bell-shaped, and has a coronet of cilia on the upper bor- 

 der. The margin of the cup, or bell, is enlarged and 



