THE FAUNA OF A COAL-PIT AT GREAT DEPTHS 161 



the bark had not been stripped. The incline wherein our 

 specimens were found was driven in 1909, and many trees 

 introduced at that time still exist there ; but, owing to decay 

 and crushing, new trees have to be erected every few weeks, 

 so that it is impossible to fix the date of the introduction of 

 the animals. It is possible also that the constant current of 

 air driven through the passages may bear with it from 

 the outside such light-bodied creatures as the flies found 

 underground. 



However they may have been introduced, the majority of 

 the species seem to have become naturalised in their new 

 habitation. For not only was there abundance of individuals 

 of flies, collembola, spiders, earthworms, and slugs, but young 

 individuals at different stages of growth were common as 

 regards the slugs, earthworms, and spiders. Small whitish 

 cocoons, apparently belonging to the last named, were also 

 found, as well as a larva, probably of the Staphylinid beetle. 

 These facts taken together seem to point to the permanency of 

 the animal occupation ; at any rate to the definite establish- 

 ment of the slugs, earthworms, spiders, and " docker " beetles. 



As regards the distributional interest of the animals 

 found, all, with the exception of the spider, are common 

 in the Forth Area, though none have been recorded, so far as 

 I know, as living in cavern conditions, apart from the earth- 

 worm Eiseniella tetrcedra and the collembolan, both of which 

 have been discovered in Mitchelstown Cave, in Ireland, the 

 latter also in similar situations elsewhere. The spider Lcssertia 

 denticJielis is an addition to the known fauna of Scotland. 



Before passing to a consideration of the animals found, it 



remains to add my grateful thanks to many willing helpers : 



To Mr John M'Dermott, who collected the material with 



great perseverance and enthusiasm during his leisure 



moments in the pit; to Mr Percy H. Grimshaw, F.E.S., 



F.R.S.E., who identified and supplied the notes regarding 



the flies and beetles ; to Dr Randall Jackson for identifying 



the spider; and to Mr F. M. Calder for information 



regarding the pit. 



{To be continued) 



-\l X 



