Microscopical Essays. 



291. Vorticella Multiformis. 



Vorticella viridis, opaea, varia, veficulis fparfis. Green, opake* 

 variable vorticella, with veficles fcattered about the body. 



This is fo like the preceding one, that it needs no further 

 defcription. Is found in fait water, and the veficles are larger. 



292. Vorticella Nigra.. Fig.. 36 and 37, Plate XXVI... 



Vorticella trochiformis nigra. Top-fnaped black vorticella, 



To the naked eye they prefent themfelves as fmall 'black points 

 fwimming on the water ; through the mierofcope it appears as a 

 little conical corpufcle, opake,, obtufe,. and ventrieofe at one ex- 

 tremity, the other acute ; when it extends the extremities, two- 

 little white hooks come into fight, by their afliftance it moves in 

 the water,, and it is probable,, from fome circumftanees, that they 

 inclofe a rotatory organ. It is in continual motion, vacillating on; 

 the top of the water. Is found in Auguft, in meadows that are 

 covered with water, a the rotatory organ, b the two fmall hooks,, 

 v £ the acute end.. 



293.. Vorticella Cucullus. 



Vorticella elongata, teres, apertura oblique trunoata.. This- 

 vorticella is long, round,, the aperture or mouth obliquely trun- 

 cated. 



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