• Microscopical Essays. 643 



To the naked eye it appears like the vorticella focialis, but is 

 diftinguifhed from it by always adhering to the fides of the veflel 

 in which it is placed. On examining it with a magnifier, a long 

 very fine pedicle is perceived flicking to the fides of the veffels, 

 from which proceed an innumerable quantity of cryftalline pel- 

 lucid pearls, which, together with the ftalk, are varioufly agita- 

 ted in the water. They fometimes move feparately, fometimes 

 together, are fometimes drawn down to the root, and in a mo- 

 ment again expanded. 



XVII. Brachionus. 



Vermis contraftilis, tefta tectus, ciliis rotatoriis. A worm ca- 

 pable of contracting, covered with a fhell, and furnifhed with 

 rotatory cilia. 



358. Brachionus Striatus. Fig. 64 and 65, Plate XXVI. 



Brachionus univalvis, tefta ovata ftriata, apice fexdentata, 

 bafi integra, cauda nulla. Univalved brachionus, the fhell oval 

 and filiated, fix notches or teeth round the upper edge, the bafe 

 whole or even, without a tail. 



The fhell is oblong, pellucid, and capable of alterations in it's 

 figure. The apex (a) truncated, with fix fmall teeth on the edge 

 'of it, twelve longitudinal flreaks down the back, the bafe obtufe 

 and fmooth. The teeth are occafionally either protruded or re- 

 traced ; on the other fide of the fhell, towards the tail, there are 

 two little fpines or horns (c). • 



1 



The 



