94 ARACHNOIDEA. 



CASE render an acceptable service to naturalists by giving a general 

 resume of the state of our knowledge regarding them in more 

 detail than we shall do for any of the other orders of insects. We 

 shall first offer a few hints which may be useful in assisting the 

 reader, in a general way, to determine the place or genus of any 

 species he may have in hand. 



In the first place, the locality where they are found will be a 

 great assistance. 



The first section of the Trombidiinae or spinning mites belong 

 to the genus Tetranychus, or red spider of gardeners. These are 

 found on plants, and are readily distinguished from their con- 

 geners by their very minute size, and by being semi-transparent ; 

 some species have little colour, and, to one unacquainted with 

 them, might seem not unlike the cheese mites, but the form of 

 their palpi and other characters, which will be found noticed as 

 we go along, at once distinguish them from that group. 



The Trombidiidse, or harvest mites, are distinguished by their 

 brilliant colouring, which is generally scarlet or some modification 

 of red. Some, however, are marked with black or brown. They 

 are usually found on the ground or under stones. 



The Bdellidse, or snouted harvest mites, have the same character 

 of colouring, but are distinguished, among other things, by their 

 mouth being protruded like a snout, and usually narrowed behind 

 the palpi, giving them, the appearance of having a head and neck, 

 and still more by their palpi being bent at right angles in their 

 midst like those of many weevils. 



The Hydrachnidae are merely Trombidiidae converted into water 

 mites, and adapted for their different spheres of life. They have 

 the same general arrangements of structure, and retain the brilliancy 

 of their colouring \ some being as bright scarlet as the harvest 

 mites, and others having a distribution of colouring still more 

 startling. 



The Gamasidae are, for the most part, parasitic, chiefly on in- 

 sects, but some on other animals, or ranging about free. They 



