140 NATURAL HISTORY 



the T. cJiaron, and has a cluster of long bristles at each 

 extremity. 



325. Kkrona cahitiiim has three hooks at the ante- 

 rior, and two long spines at the posterior ; it is covered 

 with a shell, and sometimes appears surrounded with 

 cilia. Figure 187 is a magnified view of it swimming. 



327. Kerona myiilus {Stylonychia, E.) — The form of 

 the body is oval : it is destitute of a shell, though the 

 extremities appear as if protected by a thin plate. The 

 anterior is furnished with two horns, which, when in 

 motion, produce a current towards the mouth. In some 

 specimens the margin is surrounded with cilia ; in 

 others, they are only observed at the extremities : near 

 the posterior are two long spines. 



328. Kerona lepus {? Oxytricha lepus, Bory).— This 

 animalcule is of an ellipsoidal form : the fore part, w^hich 

 is furnished with cilia, is smaller than the posterior, and 

 is beset with bristles. Size, 1 -500th of an inch. 



329. Kerona histrio {Sti/lonycMa, E.) — This animal- 

 cule is shewn, magnified, at figure 199: the anterior is 

 furnished with styles, and five hooks may be seen on the 

 under side, as also a cluster of long cilia near the poste- 

 rior extremity. 



330. Kerona ci/pris. — This species is pear-shaped, not 

 symmetrical, and the mouth at the longest end is fur- 

 nished with cilia and a few hooks, which, by their vibra- 

 tion, occasion a current in the water. 



331. Kerona haustrum is nearly circular, with the 



