Bibliographical Notices. Ill 



BIBLIOGRAPHICAL NOTICES. 



Monographie des LibelluUdees d' Europe. Par Edm. De Selys Long- 

 champs, Membre de plusieurs Societes savantes. 



We do not know a more noble tribe of Insects than the Dragon- 

 flies — the wonderful ceconomy, perfect organization, exquisite struc- 

 ture, beautiful colouring and unusual magnitude of these Insect- 

 hawks combine to render them worthy the attention of the philoso- 

 pher as well as of the naturalist. In the earlier stages of their 

 existence they live as larv?e and nymphse, entirely in the water, 

 where they are actively engaged in entrapping other insects to 

 satisfy their cruel appetites, possessing, contrary to the greater por- 

 tion of this class of animals, the power of locomotion in their pupa 

 state, and being furnished with a remarkable mask, which is pro- 

 jected at will to seize their victim. When they emerge from their 

 aquatic habitation and assume the perfect state, to soar along the 

 banks, or skim over the surface of a stream, in search of insect prey, 

 the evolutions of the larger species are very remarkable ; they dart 

 forward, halt or wheel with the most perfect precision, whether it 

 be in sportive play or in the pursuit of other insects, which they cap- 

 ture and devour in their flight, not sparing their kindred species of 

 equal size. 



On examining living specimens of the larger kinds, the volume of 

 their compound eyes will be found to exceed that of any other in- 

 sect, and the beauty and perfection of these organs is scarcely to be 

 equalled : their powers of vision must be wonderful, for they can, no 

 doubt, take in the whole surrounding field of vision at once, and in 

 all probability to a very great distance : their exquisite wings rival 

 the most beautiful lace-work, and their bodies are generally painted 

 with Nature's liveliest colours, which unfortunately fade after death ; 

 otherwise nothing could be more beautiful than a collection of Li- 

 bellulid?e arranged in a cabinet ; this misfortune is however in a 

 measure mitigated by emptying and stuffing the thorax and bodies 

 as soon as they are killed. Their enormous mouths and powerful 

 organs of manducation are well adapted to their predatory habits ; and 

 such is their ferocity, that when under restraint they have been 

 known to satisfy their inordinate appetites by devouring their own 

 bodies ! From some unknown causes, the Dragon-flies, like various 

 other insects, occasionally increase to excess, when they migrate 

 in clouds like the Locust, travelling hundreds of miles in search of 

 food, their route being guided by the nearest stream, and followino- 

 the current they pursue their course in countless myriads. 



Greatly as naturaUsts and scientific men are indebted to DeGeer 

 and Roesel for their valuable researches relating to these insects, 

 volumes might still be written in the investigation of their oeconomy 

 without entering upon their specific distinctions ; it is not therefore 

 surprising that so interesting a subject should have engaged the at- 

 tention of many authors who have lately undertaken to characterize 

 the genera and identify the species. It is to be regretted that the 



