author's preface. vii 



accord with it in scarcely any single detail. The extreme 

 variability of male Lucanid^ is the cause of exceptional 

 difficulty in identification and, as a result, the nomenclature 

 of the group is greatly complicated. Only the study of series 

 sufficient to link uji the different phases can resolve the numer- 

 ous problems that arise. Since many Indian species are still 

 known by only a very few examiiles, or even a single one, it 

 cannot be hoped that finality in nomenclature has been achieved 

 in this work. The present attempt, with its rather extensive 

 revision of antecedent work, will itself inevitably need 

 revision when further materials have accumulated. It may 

 at least be hoped that this volume, by bringing together the 

 very scattered records in comprehensive form, will serve to 

 stimulate interest in a very remarkable and attractive group 

 of insects. 



To illustrate vdih anything like completeness insects so 

 variable as the Lucanid^ would require figures of many 

 examples of each. Such series, in very many cases, are not 

 at present to be found in any collection, and I have been 

 obliged to content myself with one figure of nearly every 

 species of both sexes of a considerable number and of more 

 in a few representative cases only. The photograjjlis, with 

 a few exceptions, are of the exact size of the originals and in 

 many cases are of type-specimens, either so designated by the 

 author of the name or one of the original series from which the 

 species was described. The figures not of the actual size of 

 the specimens are indicated in the " Explanation of the 

 plates". 



