2i6 ARACHNOIDEA. 



CASE individuals in most of the Oribatidre, and M. Nicolet traced the 



XIII. 



changes in a number of them. We show the difference in the 

 present species in the above cut. 



This species is found from November to March, beneath the 

 shghtly detached bark of fruit trees, such as the pear, where they 

 live in society, remaining very quiet during the winter months ; 

 they also secrete themselves and breed under the lichen, which 

 often covers the trunks and branches of fruit trees. Various reme 

 dies have been recommended for getting rid of this mite, but as 

 it is a friend to be encouraged, and not an enemy to be repressed, 

 it is unnecessary to detail them. 



M. Boisduval, in his " Entomolgie Horticole," speaks of an 

 Acarid, which he calls Acarus Pyri, as being relatively very large, 

 globular, vesicular, of a red brown, rather transparent, very visible 

 to the naked eye. It, says he, lives on the large branches of the 

 pear-trees which have been gnawed inside by the Leopard moth ; 

 they are usually found in small crowded groups at the bifurcation 

 of the branches. It may possibly be an Oribatid, although it is 

 not likely that it could be this species, with wliich M. Boisduval, 

 was obviously famiUar. 



No. 9. Dam^us auritus {Nlc.).—^. Magnified sketch of ditto, copied from M. 

 Nicolet's figure. 



This species is as common as the preceding species in France, 

 and very probably may also be found in this country, although 

 probably hitherto confounded with the D. geniculatus. 



Genus Leiosoma [Koch). 



Cephalothorax with plates, and tarsi with three heterpdactyl 

 claws. 



No. ic. Leiosoma nitens ((7^;v.\— iO. IMagnified sketch of ditto, copied from 

 Nicolet's figure. 



Occurs near Paris. 



