Microscopical Essays* 



437 



Fig. 16 reprefents four that were formed by the feparation of 

 the two bulbs, reprefented in. the foregoing figure. 



VORTICELLA PyRARIA. 



Compofita, floribus mutieis obovatis, tentaculis bigeminis ftirpe 

 ramofa, Fig. 25 and 26, Plate XXII. Compound, with beard- 

 lefs oval florets, two double arms, the Hem branched. Lin. 



It is fomewhat of a pear fhape, thebafe is pellucid, the top- 

 truncated ; the lateral arms, which are a pair on each fide, can- 

 not be diftinguifhed without fome attention ; they are fometimes 

 to be feen difengaged from the pedicle, and rolling fwifily in a 

 kind of circle. 



VORTICELLA Cr AT^EG ARIA* 



Vorticella compofita, floribus mutieis globofis, tentaculis binis^ 

 flirpe ramofa, Fig. 40, Plate XXII. Compound, with globous 

 naked florets, two tentacules, and a branched ftem. 



Thefe vorticellse are to be found in the month of April, both 

 in the mud, and upon the tail of the monoculus quadricornis ; 

 they are generally heaped together in the manner in which they 

 are reprefented in the figure ; they are of a fpherical form, and 

 united to one common ftalk. They are alfo often to be found 

 without any pedicle, the body is rather contracted, the aperture 

 is circular, and furrounded with a marked margin ; it has two 

 fmall arms ; with a deep magnifier, a vehement rotatory motion 

 may be feen \ they fometimes feparate from the community, and 



