272 MICROSCOPY FOR BEGINNERS. 



I think, all the water -mites prefer. A moment's ex- 

 posure to the direct sunlight out of the water is 

 fatal. 



6. ITAX (Fig. 177). 



The anterior coxse are in contact by their entire 

 length, and the posterior extremities of the two anterior 

 groups on each side are also often in contact, thus ap- 

 pearing to press the mouth between them. The posterior 

 coxse are also in contact for their whole length, but they 

 do not touch those of the opposite side of the body. The 

 fourth coxa, or the one belonging to the 

 most posterior leg, is usually much larger 

 and broader than any of the others. The 

 two ventral plates are narrow and curved, 

 ^ ie tubercles on each of them being round- 

 ed and translucent. The front pair of legs 

 are long and curved, the hairs on them being bristle- 

 like. When the mite walks these legs are held rigidly 

 in front. The color of the body varies, as it does in the 

 other forms. A yellow Atax is not uncommon in our 

 ponds and shallow, slowly flowing streams. 



7. LIMNOCHARES (Fig. 178). 



This mite may be recognized by its habit of always 

 walking. It never swims. In this it differs from all 

 the other known forms of fresh-water mites. The eyes 

 are four, and are arranged on a lanceolate plate (Fig. 

 178, much enlarged), two on each side, with a central 

 rounded projection between them in front. They are 



