120 Probable Number of Insect Species, 



doubtless, be ascertained to be inhabitants of this country. 

 In addition to which, the aberrant ichneumons (ichneumones 

 adsciti of Nees von Esenbeck) are very numerous, nearly 200 

 having been indicated by Mr. Curtis as British ; whilst, of 

 the minute families of Chalcididae and Proctotrupidae (/chneu- 

 mones minuti Lin,) there cannot be fewer than from 1000 to 

 1500 species inhabitants of this country. 



From this immense numerical increase in groups, it is 

 evident that, in order to obtain a sufficiently practical mode 

 of studying them, it is essential that very numerous divisions 

 should be established, founded upon minor variations of 

 structure ; whereby the student may be saved the trouble of 

 wading through the characters of some hundreds of species, 

 by arriving at once at the inferior group to which his insect 

 is referable : and it has been ascertained by practice, that it is 

 much easier to recollect these minor groups when named, than 

 when designated by stars, daggers, &c, after the old fashion.* 

 It has, indeed, been objected, that, by this practice, every 

 species was becoming a genus ; but this is far from being the 

 case : for, although many individual species exhibit such a 

 diversity of structure as to warrant their establishment as 

 distinct groups, yet many of these inferior groups are ex- 

 tremely numerous in species, some of them containing SO, 

 60, 100, or even 200 species (as in the restricted genus Cicin- 

 dela), the characters of which, as distinct sections, are not of 

 higher value than those which distinguish the individual 

 species forming distinct genera. 



Fully coinciding, therefore, in the propriety and advantage 

 of the establishment of these minor groups, I subjoin the 

 characters of a few, founded upon different species of the 

 very minute but highly beautiful tribe of parasitic Chalcididae. 

 I have followed the general practice of giving the essential 

 characters in Latin, in order that they may be recognised by 

 foreign entomologists, who may be unacquainted with the 

 English language. Some of our English authors have, in- 

 deed, lately thought fit to omit these Latin characters : a 

 practice which appears to me to be attended with much 

 inconvenience, inasmuch as its consequence will, in all pro- 

 bability, be, that our new species will be republished, by some 

 Swedish or Russian naturalist who does not understand a 

 word of English, with a different name ; whereby still greater 

 confusion than at present exists, will be created in specific 

 nomenclature. 



* It must be borne in mind, that I am here speaking of the practical, ami 

 not the natural, method of studying natural history. 



