xvi PSEUDOSCORPIONS 431 



in this country, twenty British species have been recorded, and 

 the known European species number about seventy. 



As might be expected from their small size and retiring 

 habits, little is known of their mode of life. They are 

 carnivorous, feeding apparently upon any young insects which 

 are too feeble to withstand their attacks. The writer has on 

 two or three occasions observed them preying upon Homopterous 

 larvae. As a rule they are sober-coloured, their livery con- 

 sisting of various shades of yellow and brown. Some species 

 walk slowly, with their relatively enormous pedipalps extended 

 in front and gently waving, but all can run swiftly back- 

 wards and sideways, and in some forms the motion is almost 

 exclusively retrograde and very rapid. A certain power of 

 leaping is said to be practised by some of the more active species. 

 The Chernetidea possess spinning organs, opening on the movable 

 digit of the chelicera. They do not, however, spin snares like 

 the Spiders, nor do they anchor themselves by lines, the sole use 

 of the spinning apparatus being, apparently, to form a silken 

 retreat at the time of egg-laying or of hibernation. 



External Structure. The Chernetid body consists of a 

 cephalothorax, and an abdomen composed of twelve segments. 

 The segmentation of the abdomen is emphasised by the presence 

 of chitinous plates dorsally and ventrally, but the last two dorsal 

 plates and the last four ventral plates are fused, so that ordinarily 

 only eleven segments can be counted above and nine below. 



The cephalothorax presents no trace of segmentation in the 

 Obisiinae (see p. 437), but in the other groups it is marked 

 dorsally with one or two transverse striae. The eyes, when 

 present, are either two or four in number, and are placed near 

 the lateral borders of the carapace towards its anterior end. 

 They are whitish and only very slightly convex, and are never 

 situated on prominences. Except in Garypiis there is no trace 

 of a sternum, the coxae of the legs and pedipalps forming the 

 ventral floor of the cephalothorax. 



In the Obisiinae a little triangular projection in front of the 

 cephalothorax is regarded by Simon a as an epistome. It is absent 

 in the other sub-orders. 



The abdomen is armed, dorsally and ventrally, with a series of 

 chitinous plates with membranous intervals. The dorsal plates 

 1 Arachnides de France, vii., 1879, p. 2. 



