* 
38 PLA TrE., XXVIL 
This fpecies of Vorticella appears, without the affiftance of a micro- 
fcope, as {mall black fpecks, fwimming en the water, particularly in 
meadows which are inundated. "They are conftantly in motion; and 
two fimall white hooks are perceptible by glafles at 1—1; by the help 
of thofe it is fuppofed to fwim, or they may inclofe fome rotatory or~ 
gan. ‘The infect is opaque, 
PLATS 
