142 INSECTS. 



differs from this, and indeed from all others, in the singular 

 length of its neck, which, slender itself, and terminated 

 by a gradually widening and flattened head capable 

 of great freedom of motion, gives a most curious snake- 

 like appearance to the insect. The abdomen is small 

 and short, and the thorax, placed between this and the 

 head and neck, is nearly in the centre of the insect. This 

 snaky look, added to the possession in the females of a 

 long ovipositor, has an uninviting effect; and not long 

 ago the writer received a specimen with an urgent request 

 for an opinion as to the probable extent of the injury 

 which it might have inflicted on a baby on whose face it 

 was found. 



The Snake-fly and its larva are insect eaters, the latter 

 living under the bark of trees. The pupa is inactive in 

 its earlier stage, but is said to be capable of walking 

 immediately before arriving at perfection. There are five 

 English species of Eaphidia. 



The insects hitherto described are probably familiar to 

 the reader in their winged state only ; there remains a 

 family of which the larva and pupa, and in some cases 

 a wingless imago, are but too well known. The com- 

 monest species of these is a little whitish, semi-trans- 

 parent creature which we find abounding in books 

 (especially such as are rarely used), old papers, collec- 

 tions of plants, of insects, &c. &c. This little insect is 

 the Psocus pulsatoria, the latter name from a sound, 

 similar to that produced by the death-watch, which is 

 heard to proceed from its haunts. There seems to be 

 some doubt, however, as to the fact of this sound being 

 caused by the Psocus. The Book-louse, as the Psocus 

 is commonly called, has always been considered very 

 destructive to the books and collections in which it is 



