1 animAlcula of infusions. 151: 



\vhen I had no drauglitfinan to defign thern^ 

 therefore I mud content myfelf with a fimple 

 defcrlption. One fpecies reprefents an infinitely 

 minute hedgehog, or rather, fea hedgehog, being 

 'of a fpherical figure, and the whole furface co- 

 vered with long ^pointed prickles. The anterior 

 part is diftingUifhed by advancing firft, and pro= 

 duciiig the ufual vortex, by vibrating the fpin'es : 

 the reil: are in confi.ant agitation when the animal 

 advantes. Another fpecies refembles the fegrnenf 

 bf afphere or a hemifphere, and is entirely co- 

 vered with fpines : thofe on the convex part 

 ferve for fins • others, appropriated to fornl the 

 Vortex, are fituated on the feftion or plane of the 

 hemifphere, which is always the anterior part of 

 the animal. All are difimited ; and their fepara- 

 tioh feerned to fmooth the animal's body, w'liicli. 

 can move-any number of fpines at a time. Ac^ 

 cording to the number in motion, its aO.ivitjj 

 flownefs, and even the vortex is greater, Thei'e 

 two fpecies which commonly inhabit the tremeila, 

 and are of a eoloffal iizQ compared with many 

 other infufion anim.alculaj divide longitudinally, 

 but the divifion begins at .the pofterior part. A 

 very faint cleft was feeh there as ufual^ which 

 extended more on. the animal's body, ana at 

 length divided it into two portions eivactly ecprJ, 

 They were not, as eafily might be imagined, two 

 halves only, but, before the dlvificn finilhed, two 

 K 4 complete 



