I 39 1 

 PLATE XVil. 



VORTICELLA URCEOLARIS* 



GENERIC CHARACTER. 



A fmall animal, with a vafcular cup; the mouth is at one cn«l 

 ^filiated, and capable of being contracled ; the ftem fixed* 



SPECIFIC CHARACTER. 

 Single, with a fliort tail, and toothed mouth. 



This Animaicum Is but perceptible to the naked eye, appearing as 

 »t fmall white fpeck; the microfcope difcovers the external covering to 

 be fo tranfparent, that all the motions of the animal within are per- 

 feclly diftincl* It hath a double rotatory inftrument, which, however, 

 it can conceal or (hew at pleafure j and it hath power to protrude the 

 head and tail as at Fig. i. or to contract them within the external coat 

 or covering, as at Fig. 2. — When the animal intends to difplay its 

 rotatory inftrument, it forces its tail through the hole at the extremity 

 of the outer coat, and afHxes it to whatever fubftance is near ; but 

 when it fv/ims, it moves its tail backwards and forwards to affift it. 



They are found in river, or ftagnant, water* 



G FIG 



