BRITISH SPECIES OF FALSE-SCORPIONS. 201 



special characters unite them as one of the most obvious and well 

 marked groups of their class. Externally (as before observed) they 

 bear a very strong resemblance to the true scorpions, and at first 

 sight they might well be considered minute examples of that 

 group, simply destitute of a tail ; but they differ notably from the 

 true scorpions in respect tp their respiratory system and other parts 

 of their anatomy. Perhaps their closest natural affinities are to 

 some groups of the extensive order Acaridea (or mite-tribes) ; and 

 in regard to some of their characters they approach the order 

 Solpugidea. These last, however, are exclusively exotic, and 

 comprise, comparatively speaking, only a few species of one of the 

 most homogeneous and distinct of the various Arachnidous orders. 



Having thus shortly mentioned their more general characters 

 and position it will be necessary here to give a rather more detailed 

 description of a false- scorpion. (See plate A, figs 1 to 6.) I shall 

 use as few technical terms as possible, though, of course, to some 

 extent it is not always possible to avoid technical terms, inasmuch 

 as there are no others available for describing many portions of 

 structure. 



CLASS : ARACHNIDA. 

 ORDER CHERNETIDEA. 



In treating of this group some years ago (1875, Encylop. 

 Brit. Ed. IX., vol. ii., p. 282) the strong external resemblance of 

 its species to the true scorpions, led me to include it with them as 

 two sub-orders of the order Scorpionidea. Subsequent study has 

 led me to conclude, with Mons. Eugene Simon, that in spite of 

 their superficial resemblance to the true scorpions the essential 

 differences between these two groups necessitate their separation 

 into two distinct Orders. 



The Ceplialotliorax and Abdomen of the Chernetidea form 

 together an elongate-oval or oblong figure ; these two portions being 

 sessile or fitting up close to each other without any distinct connect- 

 ing-pedicle. The Ceplialotliorax frequently shews the originally 

 separate caput and thoracic segments by more-or-less well-marked 

 grooves or indentations. The surface (or epidermis) of the 



