Spiders and Mites 



193 



Of mites there is one rather small family (Hydrach- 

 nidae) of aquatic habits. These water-mites are minute, 

 mostly rotund (sometimes bizarre) forms with unseg- 

 mented bodies, and four pairs of long, slender, radiating 

 legs. One large species (about the size of a small pea) 

 is so abundant in pools and is so brilliant red in color 

 that it is encountered by every collector. Others, tho 



\ 



FIG. 100. An overturned female crawfish (Cambarus bartoni), showing 

 the eggs attached to the swimmerets (four thoracic legs broken off). 



smaller, are likewise brilliant with hues of orange, 

 green, yellow, brown and blue, often in striking patterns. 

 Water-mites, even when too small to be distinguished 

 easily by their form from ostracods or other minute 

 Crustacea are easily distinguished by their manner of 

 locomotion. They swim steadily, in one position; 

 not in the jerky manner of the entomostraca. The 

 strokes of their eight hair-fringed swimming feet come 



