FALSE-SCORPIONS 101 



world-wide distribution, others are rare and local. As a rule they 

 are sober-coloured animals, their livery consisting of various shades 

 of yellow and brown. 



A wide variety of habitats are colonised, the majority of species in- 

 habiting soil and decaying vegetation while others live under stones 

 and the bark of trees. None is parasitic: Chelifer cancroides has oc- 

 casionally been recorded on man but it is probably merely phoretic 

 (see below). This species, Allochernes italicus, Cheiridium museoruniy 

 etc., frequently live in human habitations. Microhisium femoratum 

 lives exclusively in moss and members of the genus Neobisium are 

 nearly always found in moss and humus: the species of Chthonius 

 are nearly always found under stones while the genus Chernes 

 includes bark-inhabiting forms. Species such as Microhisium dumi- 

 cola and Neobisium sylvaticum that walk in the open on plants and 

 bushes are extremely rare, but cavernicolous false-scorpions are 

 relatively numerous, although they belong almost exclusively to 

 the genera Neobisium^ Roncus and Chthonius. Quite a number of 

 species are myrmecophilous and live in the nests of ants: Donis- 

 thorpe (1927)* records the following amongst the British fauna, 

 Chthonius ischnocheles, Neobisium muscorum, Roncus lubricus, Micro- 

 creagris cambridgei^ Pselaphochernes scorpioides and Allochernes 

 wideri. Neobisium maritimum, Chthonius halberti and the large 

 Garypus beauvoisi have a littoral distribution and are found in cracks 

 in rocks between tide-marks on the sea shore while Neobisium 

 muscorum and several other species occur in damp seaweed at the 

 water's edge. 



A number of species such as Withius subruber^ Cheiridium musco- 

 rum and Toxochernes panzeri are often associated with stored food 

 products in warehouses, where they inhabit extremely dry environ- 

 ments: they also occur in birds' nests in hollow trees. In view of 

 their small size it is obvious that their powers of water-retention 

 must be extremely efficient. A number of other species are partial 

 to heaps of manure and one or two cling to the legs of flies and 

 other arthropods as a means of dispersal (see below). The well- 

 known 'book-scorpion' Cheiridium muscorum y already mentioned, 

 has been known to live in human habitations since the time of 

 Aristotle, for he wrote: 'In books other small animals are found, 

 some of which are like scorpions without tails,' and in this country 



