OF ANIMALCULES. 139 



llieir minuteness : one of them is shewn at figure 191, 

 Another mode of propagation is from spawn ; and, as in 

 the case of the Kolpoda cucullus, a dissolution of part 

 of the animalcule is effected at the same time it casts the 

 spawn. The form of the creature varies greatly, and Dr. 

 E. states, that unless he had actually observed these 

 changes, he might have mistaken it at different times 

 for so many distinct species. If they are fed with colour- 

 ing matter, their polygastric sacs may be readily dis- 

 cerned, as also a duct near the extremity. Length, 

 l-240th of an inch. 



324. Kerona rastellum, — This animalcule is nearly 

 circular, with a small projection at one edge : the upper 

 surface is covered with three rows of hooks. Found in 

 river-water. 



323. Kerona lyncaster. — This is nearly of the same 

 form as the preceding species, but has a projection at 

 each extremity : the anterior is furnished with bristles, 

 the posterior inflected backwards, and the under surface 

 covered with stout long hairs. Found among confer vae. 



324. Kerona patella is shewn at figures 1 88 and 189. 

 The body is covered with a shell, and is furnished with 

 bristles, as shewn in the sketch. The front ones are 

 strong, like hooks : these it employs, together with the 

 posterior, in walking, and when it swims it is usually 

 on its back. 



325. Kerona vawwMs.— This animalcule resembles the 

 next species, figure 187, but is fringed on one side, like 



