THE BAT-LOUSE. 645 



name, though., is quite as inappropriate as that of the Wood- 

 Louse, both words signifying creatures which belong to different 

 classes in the animal kingdom. Its colour is ochreous and 

 shining. The hinder part of the thorax is deeply waved, and 

 it is punctured beneath, with a channel down the centre. The 

 abdomen is ochreous brown, and the legs are covered with hair, 

 the tibiae being very broad and flat. It is plentiful on the com- 

 mon Bat ( Vespe7'tUio murinus), so that there is no difficulty in 

 procuring this curious insect. If a bat be killed, and taken into 

 the hand, the Nycteribise immediately crawl from beneath the 

 hairs of the dead animal, and crowd upon the hand of the holder. 

 As long as the animal is alive they remain upon it, but no sooner 

 is the life extinct than the Nycteribise desert it, and fasten upon 

 the first living being that they can find, just as has been related 

 of the Bird Flies. In some mysterious manner they know at 

 once that the life, which constitutes their home, has fled, and 

 they at once desert the empty tenement. 



Our task is now ended, and all that remains is to see how to 

 prepare — or ' set,' as is the technical term — insects which are 

 taken as specimens for the cabinet. On Fig. 1 of the accom- 

 panying illustration, the little black dot shows the spot at 

 which the pin ought to be inserted in all Beetles that are more 

 than a quarter of an inch in length. Even those of smaller 

 size can be thus treated, provided that the entomologist use 

 one of the fine pins which are employed for this special 

 purpose, and can be obtained at any of the naturalists' shops. 



The best pins are gilt, so as to prevent them from producing 

 that abominable green verdigris which is almost invariably to 

 be found springing from the spot where the pin pierces the 

 insect, and which so often covers and spoils the insect itself. 

 Beetles of smaller size should be set on little strips of white 

 card-board, some transparent cement being used for the purpose. 

 In this case, one specimen at least should be set on its back, so 

 as to show the under side, on which the entomologist often 

 finds the principal distinguishing characteristics. The same 

 rule applies to Earwigs, Grasshoppers, and their kin. It is 

 always as well to set one specimen with spread wings, when 

 those organs are preseni. 



