INTRODUCTION. 35 



LUCANID^. 

 Introduction. 



The LucANiD-^ are a fiiirly well-defined family of 

 Lamellicorn l)eetk's, many of the large forms of whicli have 

 been long kno\vni as Stag-beetles on account of the enormous 

 enlargement of the mandibles which occurs in the males. 

 Although they are always well developed and exjiosed to view, 

 it is only in full-sized examples of their species that the very 

 long and fantastic mandibles are found. In some of the small 

 forms male and female are alike, but dissimilarity between the 

 sexes is a characteristic of the group as a whole. 



Althougli in certain parts of the world, such as South 

 Africa and the Hawaian Islands, there are found Lucanid^ 

 which are without the i)ower of fliglit and \\hich perhaps pass 

 most of their lives below the surface of the ground, those dealt 

 with in this volume all appear to be active insects, possessing 

 the normal organs and functions. Unlike representatives of 

 the family found in Australia, they are not remarkable for 

 conspicuous beauty of colouring, being in general dark 

 coloured, with a certain num])er of red or yellow species, but 

 they include also a few highly decorated insects, especially 

 in the genus Calcodes. In the number of kinds to be found 

 there is perhaps no part of the world more productive than tlie 

 Indian region, from whicli 133 are here recognized as distinct 

 species out of a total for the whole world of about one 

 thousand. 



Some of the species have an extremely glossy surface, 

 although this rarely extends to the head. Others have a kind 

 of bloom, like that of a ripe plum, upon the upper surface, but 

 this is of a rather fugitive character and may be absent in old 

 and worn si)ecimens. Yet otlier forms (Dorcns cinereus, 

 Gimphaloryx opacus) are generally found with a kind of grey 

 earthy incrustation upon the up])er surface, either secreted by 

 the insect or caused to adhere by some kind of sticky secretion. 

 A few species have a covering of fine hair. All these 

 characteristics generally vary according to sex and are rarely 

 alike in both sexes. 



Like that of most Lamellicorn beetles, the body-form slu)ws 

 a fundamentally fossorial [i. e. digging) type. This has been 

 partly retained in most of the females but is generally lost in 

 the males. In the former the body is commonly nnjre 

 compact and muscular, the head deeply sunk in the thorax, 

 the mandibles short and strong, tlie antennae and legs short, 

 the front tibia? fiat and furnished with strong teeth at the 

 outer edge. In the males these characteristics are often 

 conspicuously lacking, the whole body is more loosely 



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