416 EVENINGS AT THE MICROSCOPE. 



Common as these Stylonychia are, and abundant beyond 

 all calculation, where they do occur, from their tendency 

 to self-division, they are not so universally met with as 

 their cousins, of the genus Euplotes. These are still 

 more highly organised, and will please you by their ac- 

 tivity and sprightly intelligence, I am sure. Here are 

 several individuals in the live -box at this moment. 



They differ from the Stylonychice, in having the soft 

 body covered with a plate of crystal mail, hard and in- 

 flexible, much like the shield of a Tortoise. Several 

 species have this glassy shield marked with delicate lines 

 running lengthwise ; sometimes in the form of parallel 

 ridges, as in a little species found in infusions (perhaps 

 E. charon), at others forming rows of minute round knobs, 

 as E. truncatus, the species now before us. The shield is 

 ample, considerably overlapping the soft body ; it rises 



into an arched form in 

 the centre ; and is more 

 or less round or oval. 

 The mouth is oblique, 

 and extends a long way 

 down the under surface ; 

 it is set with strong and 

 fine cilia, which also 

 spread over the front. 

 The organs of motion 



are, as before, long styles, pointed and rather stiff pro- 

 cesses, which project from beneath the shell backwards 

 and downwards, and soft hook-like uncini, which are set 

 chiefly near the fore part of the inferior surface. In the 

 species before us these are about six or seven in number, 

 but in E. charon they are more numerous. The twinkling 

 rapidity with which these little feet are applied to the 

 surface in crawling affords a pleasing sight : particularly 

 when the animal is running back- down wards on the upper 

 glass plate of the live-box. Some species have bristles 



