THE FALSE-SCORPIONS OF SCOTLAND 29 



is a close attendant on man, and lives and flourishes commonly in 

 hothouses, as well as more rarely about farm steadings. I first 

 ascertained this fact in the orchid-house of Stronvar, Balquhidder, 

 July 21, 1904; there the potted plants are set individually on the 

 top of inverted flowerpots to be beyond the ravages of slugs, and 

 the False-scorpions live inside the empty inverted pots. In the 

 hothouses of the Edinburgh Botanic Gardens it occupies similar 

 retreats and is found also under bricks and other objects lying on the 

 ground and on the shelves; individuals of the pale yellow colour 

 conform very remarkably to the similarly-coloured bricks and flower- 

 pots on which they are resting and can with difficulty be detected 

 unless they move. This species, as well as Ch. rayi, came under 

 my notice on a log in the stackyard of Newhouse Farm, Dunbar, 

 in May 1906. 



In moving slowly, Ch. tetrachelatus keeps its pedipalps forward, 

 with the pincers expanded, and moves them very neatly as 

 necessity requires to enable it to pass through narrow places. If it 

 is interfered with, it retracts its pedipalps towards the sides of the 

 fore-body and runs backwards in a series of short jerks. It shows 

 the same tendency as Ch. rayi to turn round quickly and face an 

 obstacle behind it, though specimens liberated from their nests are 

 less active in doing so than those moving free. 



I have seen this species with prey on a single occasion only, 

 near the town of Interlaken, Switzerland, in Sept. 1902; the 

 creature was carrying the food in its cheliceras. 



Chthonius tetrachelatus forms a nest for the various purposes of 

 moulting, hibernating, and bringing forth its young. Externally 

 the nest cannot certainly be distinguished from those of other 

 Chthonii and of O. mitscorum, and even internally it often shows 

 similar features. I have found the nest (Sept. 15) formed wholly 

 of earth without any lining, and infer that this species, like 

 O. musconiin, begins by making the earthen cell on the stone. 

 Thereafter a beautiful white silk lining is added to the inner surface 

 of the earthy dome and to the surface of the stone. In many nests 

 this is the whole structure ; but in the perfect nest formed for the 

 purposes of moulting and reproduction, a silk cocoon of exquisite 

 texture, and quite separate from the first lining, is made inside the 

 silk-lined nest, and the Ch. tetrachelatus lies snugly hid within this 

 inner cocoon. I have seen as many as twelve occupied nests 

 under a single stone. On one occasion, Sept. 7, 1905, I found a 

 Ch. tetrachelatus contenting itself with a narrow deep opening in a 

 stone for its nest, the entrance of which it had covered over with a 

 layer of silk alone. 



In September this species is commonly found moulting inside 

 the double-lined nests ; the creature casts off the skin of fore-body, 

 legs, and pedipalps in one piece, and after moulting is much 



