WHEEL-BEARERS. 241 



siderable swiftness through the water, turning frequently 

 on its course, and often partially revolving on its long axis. 

 When inclosed, as is often the case, by two fragments of 

 the filamentous Chara, it travels along the sides of its 

 inclosure, nibbling, as it goes, the Hocculent and sedi- 

 mentary deposits on the surfaces of the leaves. The long 

 spine-foot is commonly carried inertly after it ; when the 

 animal suddenly turns, of course the tail is bent at the 

 basal joint, but it is not habitually whisked about, as is 

 the tail of firachionus, nor is it so much used as a support 

 or turning }X)int. The animal has the power of so using 

 it, however, and of adhering with considerable force to 

 the glass of the box, or the side of a phial by its point. 



We have hitherto looked at our Botifera by trans- 

 mitted light ; and their crystalline transparency renders 

 them beautiful objects when thus exhibited. But we 

 will now look at the Whiptail by the direct light of the 

 sun upon it, condensed, but not to a burning point, by 

 the bull's-eye lens. 



It now possesses a peculiar beauty of another character. 

 The body generally is colourless as a vase of glass, but 

 reflects the rays brightly from its polished surface. An 

 advancing egg in the ovary is opaque white, as is the 

 front part of the mastax ; the stomach and the intestine 

 rilled with vegetable matter are of a yellow green ; the 

 rotating head appears of a pale blue, and the eye shines 

 out as a speck of opaque vermilion. 



With the dipping-tube I will now take up a drop of 

 water from the bottom of the Chara-j&r, allowing a little 

 of the loose sediment to flow in also. This is a random 

 cast ; we know not what we may get, though we are 

 pretty sure to catch something. Xow then for the ex- 

 amination. Ha ! here is the curious Skeleton Wheel- 

 bearer, Dinocharis podUum, ; — nay, several of them. 



This genus is remarkable for possessing true joints in 

 the foot ; not merely telescopic inversions of the skin, but 



R 



