444 



Microscopical Essays. 



All the clutter vorticellae detach themfelves from time to time 

 from the Hera, and from thefe they fwim about till they fix again 

 upon fome convenient fubftance ; the branches, when defcrted, 

 bear no more vorticellae. 



VORTICELLA DlGITALIS. 



Vorticella compofita, floribus cylindricis, unifulcatis femiclaufis, 

 ftirpe ramofa, Fig. 31, PI. XXII. Compound, with cylindrical florets 4 



Vorticella compofita, cylindrica, cryftallina, apice truncata et 

 Ma, pedunculo fiftulofo ramofa. Muller Animal Infuf. p. 327. 



This fpecies of the vorticella is very fcarce, it feems only to 

 have been feen by Roefel, who found it on the monoculus 

 quadricornis, till 1784, when it was difcovered by Mr. Muller, 

 who had fought for it feveral years before in vain. 



The body is cylindrical, cryftalline, and appears almoft empty ;^ 

 it has three pellucid points difpofed lengthways, the apex is trun- 

 cated in an oblique direction, the margin bent back. The upper 

 part contracts itfelf, and the margin then a {fumes a conical fhape, 

 with a convex furface ; there are in general but few branches 

 from the principal ftem, and thefe are lhort and thick ; it excites 

 an undulatory motion, but no hairs, nor any rotatory motion, 

 have been difcovered. Fig, 31, o and n, reprefents the vorticella 

 adhering to the monoculus quadricornis. 



VoRTl- 



