CHERNETIDEA OR FALSE SCORPIONS OF WEST LOTHIAN 215 



tinge, and the pincers and falces had a pink tinge. The falces were 

 very strong for the size of the creature, and the straight pincers were 

 kept widely extended as the creature moved. Its light colouring 

 indicated that it had quite recently entered on a free life; but all 

 my care both on this and on a subsequent occasion failed to dis- 

 cover the " nest " of the species, if indeed there be such, or any adult 

 specimens. 



Chthonius tetrachelatus, Preyss. On August 17, 1901, Mr. 

 Wm. Evans took half-a-dozen specimens under stones by the road- 

 side at Kinneil. 



Obisiitm muscorum, Leach. This species is universally dis- 

 tributed over the county. It is specially abundant in all the wood- 

 lands about Bo'ness, occurring among moss and dead leaves and 

 under stones. Along the valley of the Avon I have found it from 

 the mouth up to Crawhill ; and in the Almond valley I saw about 

 twenty nests, on 2ist April 1899, a ^ Almondell. I have also found 

 it at Abercorn and at Preston House, and have no doubt that it 

 may be found everywhere in the county. 



Common as the creature is, however, very little is known about 

 its life-history, and I venture to give a few notes on this subject. 

 As my opportunities for field-work have been restricted mainly to 

 the summer months, my observations are necessarily incomplete, 

 but they may form a convenient starting-point for further study. 

 During the winter I am led to believe that this creature leads a free 

 life, as the few nests I have found at that season have been empty. 

 Towards the end of March, Obisium muscorum begins to lay, and 

 she then forms a small white cocoon of a very close and tough 

 texture on the under side of a stone, or on the face of a rock covered 

 with sheltering herbage, or more rarely under a compact piece of 

 moss growing on a tree-stump. This cocoon is covered with small 

 pieces of sand and earth, in such a way that it harmonises well with 

 its surroundings, and appears to the uninitiated as merely a patch of 

 dirt. Into this cocoon or " nest," the female retires when about to 

 lay her eggs, where she remains till her young are hatched and ready 

 to forage for themselves. At the beginning of April, the eggs, 

 twenty to thirty in number, are attached as a small white mass to 

 the genital aperture, on the under side of the abdomen ; but this 

 white spot gradually expands till, after the middle of May, it 

 envelops the whole abdomen, with the exception of the upper 

 surface, and the creature is then embedded in the swollen mass of 

 her own eggs, which project below, behind, and round the sides of 

 the abdomen, and form a margin equal in breadth to the cross 

 diameter of the abdomen itself. At the beginning of June the eggs 

 are hatched, and the tiny white youngsters are seen at first attached 

 to the adult. By the middle of June, however, they are ready to 

 leave the nest and go forth on a free life. 



