XVUl IXTRODUCTIOX. 



The position of the Coleoptera among the Insecta has been much 

 disputed : many authors place them at the head of the class, considering 

 that their development is of a higher character than that of the other 

 orders ; if, however, we are to consider the metamorphoses the Lepid- 

 optera must precede them, and some writers are of opinion that the 

 Diptera and Hymenoptera should also be ranked before them : the 

 question after all is not a very important one, and it is almost impossible 

 to settle it with any certainty. 



The insects belonging to the old order Strepsiptera (Stylops, &c.) 

 have been for some time rightly ranked with the Coleoptera as abnormal 

 members of the order ; their true position, however, in relation to the 

 other Coleoptera can hardly be considered established. Professor West- 

 wood in his "Modern Classification of Insects," voL i., p. 34 (1839), 

 says that the number of species of Coleoptera with -which Entomo- 

 logists are actually acquainted cannot be less than 35,000, and prophesies 

 that, when the number of species of foreim climes shall have been 

 collected, the number will be doubled, if not trebled : this prophecy has 

 been strikingly verified, for upwards of 100,000 species at least must be 

 now known, and numbers of new species are constantly being found in 

 all quarters of the globe. 



The question of the classification of the various sections and families 

 is a most difficult one, and will not be here touched upon ; it is intended, 

 however, to discuss the 'classification adopted in this work at its con- 

 clusion, and various points will be alluded to under the different divisions 

 and families. The constant discovery of new synthetic forms that often 

 upset all preconceived ideas of classification of particular groups or 

 genera makes it impossible to establish any real or definite system, and 

 in fact our knowledge of the Coleoptera, their relations to one another, 

 and the proper positions that they ought severally to hold, may be said 

 to be as yet in its infancy ; except for a few broad lines that are 

 followed by all, their classification appears to be more or less artificial, 

 and too often a matter of taste and convenience, rather than of scientific 

 accuracy. 



Distribution of the Coleoptera in tinip. — Two or three supposed 

 specimens of Coleoptera have been recorded from the rocks of the 

 ]'ala?.ozoic period, but these have been proved lately not to be Coleoptera 

 at all ; the earliest known insect is a Blatta which was found in the 

 Middle Silurian strata, in France, in December, 1884; up to this time 

 the oldest known representatives of the Insecta consisted of six wings 

 obtained by Mr. C. F. Hartt in 18G2, from the Devonian shales of !N"ew 

 Brunswick ; two scorpions, however, have been found in the Upper 

 Silurian, and these, as insect-eaters, prove the existence of insects at the 

 period during which the strata were being formed. It is possible that 

 the Coleoptera existed at the end of the Palaeozoic period, but it 

 appears to be most probable that they did not appear until the com- 

 mencement of the Seer ndary period ; the earliest known undoubted 

 species are described by Ilecr from the Swiss Trias, the oldest formation 



