INTRODUCTION. 3 



structure, economy, and appearance all totally different from each other. On this account, 

 therefore, Clairville and Bonelli merit the greatest praise for the assiduity and perseverance 

 they have shewn in the study of the Harpalidte. Their labours, however, soon gave rise to the 

 complaint that every species was thus becoming a genus, and that confusion instead of order 

 was thus arising from their innovations. This complaint, indeed, has gradually died away 

 among Entomologists ; but it has, in consequence, become a charge levelled generally against 

 Entomology, by certain persons who are ignorant of the present state of the science. The 

 genus Carahus of Linnaeus has, above all others, given rise to such charges ; and it must there- 

 fore not a little surprise these critics to know, that after all the various mutilations which the 

 genus Carabus of Bonelli has undergone, it appears in the collection of M. Dejean, whose 

 catalogue, be it remembered, is very far from being extensive in extra-European insects, to con- 

 tain about twice as many species as Linnaeus has described of bis genus Carahus. In the 13th 

 edition of his Systema Naturae, the latter describes only forty-three of his genus Carahus, which 

 is a groupe of four modern families ; whereas Baron Dejean's collection contains eighty-three 

 species of the modern genus Carahus ; and I know of about forty more. No genus can rest on 

 more refined considerations than the genus Harpalus, as it at present stands ; yet Dejean's 

 catalogue contains ninety-two species, of which sixty-three are European. On looking at this 

 catalogue, we find that the average number of species Baron Dejean possesses in each of his 

 eighty-six genera made out of the Linnean genus Carabus, is ten ; that is, the same number 

 which Persoon, in his last edition of the Synopsis, describes in each of his 2280 genera of plants ; 

 and yet, as Decandolle has well observed, in the Tlieorie Elemeutaire de la Botanique (p. 222), 

 Persoon has in reality fewer genera, in proportion to the number of plants he knew, than 

 Linnaeus ; for while the former assigns ten species to each of 2280 genera, the latter naturalist 

 only allows six species at an average to each of 1260 genera. So that if 1500 species of Linuean 

 Carabus exist in collections, we may double thenumber of published subgenera, and yet allowfewer 

 subgenera, in proportion to the number of species we know, than Linnaeus did of genera in that 

 portion of nature with which he was best acquainted. So much for the observation that every 

 species is now a genus in Entomology, — an observation that has had its origin entirely in the 

 inadequate idea generally prevailing as to the number of annulose species which exist. We 

 every day hear of the difficulty of natural history having increased, and doubtless it is increasing 

 every hour : but this is owing to the number of new species which are pouring in upon us. 

 Still a great advantage has accrued to the science from the augmentation of our collections ; 

 for if the study of natural affinities was formerly impossible, it has now come within 

 the reach of every person who does not allow himself to be frightened by the multitude of 

 names which necessarily crowd the pages of the best modern works on natural history. Names, 

 after all, are only formidable when marshalled in an index ; and the difficulty they present to the 

 voung naturalist not only vanishes when it is encountered, but soon is found to be his best aid, 

 in combating difficulties of infinitely greater importance. 



With respect to my general distribution of Clairville's Adephaga, I have little more to say, 

 than that it is a sketch of natural affinities which the reader of the Horcc Entomologies will find 

 to illustrate certain questions there left in doubt. And if I have not been able to adopt that 

 exposition of these insects which has lately been given to the public by my friends MM. Latreillc 



B 2 and 



