208 EVENINGS AT THE MICKOSCOPE. 



transparent plate, resembling the bowl of a spoon in 

 form, but ending in two points which cany pencils of 

 bristles. The large dark eye is conspicuous in front, 

 and the six jointed and bristled limbs radiate from the 

 centre, projecting stiffly on all sides. The second and 

 tiiird pair are seen to be double, each giving ofi* a branch, 

 whicli is pencilled with bristles like the principal stem. 



We have not vet done with these tinv Water-fleas. 

 The sediment at the bottom of this jar of water is quite 

 aliv^e with a host of nimble atoms, some of which you 

 may see crawling np the sides of the glass. They are 

 quite distinct from either of the kinds we have been 

 examining, not only in details of structure, which is 

 more identical indeed than it seems at first sight, but in 

 habit ; for whereas they shoot to and fro through the 

 water with great force and rapidity, these can scarcely 

 swim at all ; or, if they do, it is with comparative slow- 

 ness and much apparent effort ; though over the smooth 

 side of their glass dwelling, or upon the stems of water- 

 plants, they glide along with much ease and elegance, 

 by the quick vibrations of their pencilled feet. 



The form we are now contemplating is distinguished 

 by the name of Cypris^ a genus which contains a good 

 many Bi-itish species. It is more completely inclosed 

 in a shell than even the Lynceus, and its envelope more 

 trul}"- resembles the shell of a bivalve Mollusk, for the 

 valves are open for more than three-fourths of their cir- 

 cumference ; while the portion of the back that is united 

 is sufficiently elastic to allow of some degree of expan- 

 sion, thus answering the j)urpose of a hinge. 



Now look at the elegant little creature. Its most 

 prominent feature is its two pairs of antennse, one pro- 

 jecting forwards and curved upwards, the other down- 



