362 EUCHIEIN^E. 



Subfamily EUCHIRIN^. 



This group consists of a very small number of species, peculiar 

 to the East, which for their size and aspect are amongst the most 

 striking of all beetles. Eleven in all are at present recognised, 

 of which four are found in India, two more in adjacent regions, 

 two in Southern China, one in the Philippine Islands, one (the first 

 and best known) in the Malayan Islands of Ceram and Amboyna, 

 and the last in Asia Minor and even so far westward as the environs 

 of Constantinople. These insects have no very intimate relationship 

 with any others dealt with in this volume, but present so curious a 

 combination of features as to make their actual origin and affinities 

 the subject of long-continued debate. In habits they resemble the 

 Stag-beetles (LUCANIDJE), feeding in the larval stage in and upon 

 the decaying interiors of old tree-trunks, and when mature upon 

 the sweet exudations from various trees. 



The most striking characteristic of the group is the enormous 

 elongation of the fore-legs in the males. This phenomenon occurs 

 in most of the principal groups of Lamellicornia, and in a very 

 marked degree in some DYNA.STIIWE and CETONIIN^E, hut in no 

 other group does it attain the extreme development found in the 

 EucmuiifjE, in well-developed specimens of which the fore-legs are 

 much longer tymn the body. The femur, tibia, and (in Propo- 

 macrus, but not in Eucliirus) the tarsus share in the elongation, 

 the femur and tibia especially being very slender and distorted in 

 strange irregular curves, which, in conjunction with various spines 

 and short branches given off at irregular intervals and angles, 

 produce the appearance of dry twigs, at least in the Indian and 

 Malayan species. In Propomacrus bimucronatus and P. davidi the 

 inner edge of the tibia carries a close fringe of golden hairs, and 

 the mimetic resemblance is therefore absent, so that no adequate 

 explanation of the phenomenon is supplied by the theory of pro- 

 tection afforded to the insects by the mimetic assimilation to their 

 environment ; although it seems probable that the particular forms 

 assumed by these extraordinary limbs in the majority of the 

 species may be accounted for in this way. A further difficulty is 

 presented by the fact that the modification is confined to the male 

 sex the one which less requires protection for the sake of the 

 continuance of the species, its effective life being shorter than that 

 of the female. 



The unwieldy fore-legs have their joints so formed as to be 

 capable of an altogether exceptional degree of movement, allowing 

 the femora to be thrown back over the sides of the elytra and the 

 tibiae doubled upon them, so that in the position of rest the limbs 

 are packed closely against the body. According to A. R. Wallace 

 the beetles are sluggish (he referred to Euchirus longimanus) and 

 " drag themselves lazily along by means of their immense fore- 

 legs." A feature of some importance is the complete absence 

 from the front tibia of the male of the movable terminal spine or 



