COLEOPTEEA. 



LAMELLICOENIA. 



THIS is perhaps the most sharply defined of all the largo series into 

 which the Coleoptera have, for convenience sake, been divided : it 

 contains two strongly-marked families, the Lucanidse and Scarabaidee, 

 which are distinguished by having the antennae terminated by a distinct 

 and usually large club, which is composed of from three to seven lamella; 

 or plates : these in the Lucanidse are immoveable, and the club is pec- 

 tinate, but in the Scarabaeidai they are in some cases capable of being shut 

 closely together or opened like the leaves of a book, while in others they 

 are received into the first joint which is hollowed. The chief pecu- 

 liarity, however, that strikes the ordinary observer, with regard to the 

 Lamellicornia generally is the immense development of the mandibles in 

 many of the species, and more especially the great horns that arise from 

 the head, thorax, and clypeus of the males : the use for which these horns 

 are destined has given rise to much discussion. Mr. Darwin (" Descent 

 of Man," page 297) says "that the extraordinary size of the horns, and 

 their widely different structure in closely-allied forms, indicate that they 

 have been formed for some purpose ; but their excessive variability in the 

 males of the same species leads to the inference that this purpose cannot 

 be of a definite nature. The horns do not show marks of friction, as if 

 used for any ordinary work. Some authors suppose that as the males 

 wander about much more than the females, they require horns as a 

 defence against their enemies ; but as the horns are often blunt, they do 

 not seem well adapted for defence. The most obvious conjecture is that 

 they are used by the males for fighting together ; but the males have 

 never been observed to fight ; nor could Mr. Bates, after a careful 

 examination of numerous species, find any sufficient evidence, in their 

 mutilated or broken condition, of their having been thus used ; " the 

 latter remark, of course, applies only to the species with largely 

 developed horns, as those in which the mandibles aro much developed 

 (e.g. Lucanus) fight very fiercely ; Mr. Darwin comes finally to the 

 conclusion that the horns have been acquired as ornaments, nnd that this 

 hypothesis agrees best with the fact of their having been so immensely 

 and yet not fixedly developed, and concludes his remarks on the group 

 VOL. iv. B 



