xvin HETEROSTIGMATA NOTOSTIGMATA 473 



(iv.) The CHEYLETINAE are remarkable Mites with fleshy, semi- 

 transparent body, and enormously developed raptorial pedipalpi, 

 which are extremely formidable weapons of attack. They do 

 not creep or run like most Mites but proceed by a series of short 

 leaps. Cheyletus is the principal genus. 



The curious genus Syringppliilus, which is parasitic in the 

 interior of birds' feathers, appears to be a degenerate Cheyletine. 



(v.) The ERYTHRAEINAE are minute, active Mites, usually red 

 in colour, free-living and predaceous. 



(vi.) The TEOMBIDIINAE include most of the moderate-sized, 

 velvety red Mites which are commonly known as " Harvest-mites," 

 and their larvae, the so-called Harvest-bugs, frequently attack 

 man. Trombidium holosericeum is a well-known example. 



Sub-Order 6. Notostigmata. 1 



This sub-order has been established for the reception of the 

 curious genus Opilioacarus. 



Fam. Opilioacaridae. Mites with segmented abdomen, leg- 

 like palps, chelate chelicerae, and two pairs of eyes. There 

 are four dorsal abdominal stigmata. Four species of the sole 

 genus Opilioacarus have been recorded, 0. ser/nientatxs from 

 Algeria, 0. italicus from Italy, 0. arabicus from Arabia, and 

 0. platensis 2 from South America. 



1 With, Vid. Medd. 1904, p. 137. 2 Silvestri, Rcdia, ii., 1904, tasc. 2, p. 257. 



