256 EVENINGS AT THE MICROSCOPE. 



of black on its back, about one-sixth of an inch in di- 

 ameter. You may notice the effectire oars which tlie 

 legs form by means of their thick fringe of hair, and in 

 particular the power which the hind pair possess by 

 reason of the enormously by dilated hip-joint, aiFording 

 space for broad and powerful muscles. 



The structure of the mouth differs greatly from the 

 same parts in the Cheese-mite. The palpi here are long 

 and perfectly free throughout ; the fourth joint is long 

 and slender, and is curiously hollowed at the end to re- 

 ceive the terminal joint, which forms a short claw, and 

 which falls down upon the former. The mandibles, too, 

 are not pincers, but consist each of a thick joint cut off 

 obliquely behind, like the nib of a pen, while the other 

 extremity is blunt and broad, and bears a strong curved 

 claw ; the lip is oval, and cleft in the middle, and is 

 wedged in between the bases of the first pair of legs. 



