SCAKAEJEI D^E. 



213 



beneath the clypeus, the margin only being visible in certain 

 cases. 



The subfamily is remarkable for the size of many of its mem- 

 bers, some of which are amongst the largest of the Coleoptera, 

 and also for the extraordinary horns and prominences on the head 

 and prothorax of many of the males. Dynastes hercules reaches 

 160 mm. (almost six inches) in length, and the species of Mecjasoma 

 are even more massive than this. 



Fig. 95. — Xylotrupes gideon male (natural size), with outline of female (a), and 

 outlines of anterior part of males of maximum (b), intermediate (c), 

 and minimum (d) development. 



The formation of the horns and excrescences is most remarkable, 

 and their significance is not known; they do not appear to be 

 used for any work, fossorial or otherwise, as they show no marks 

 of being worn, and they are certainly not used for fighting, as 

 they are very seldom broken or mutilated ; in fact they seem to 

 be an encumbrance rather than an advantage. Darwin (Descent 

 of Man, 1st edition, i, p. 371), after discussing the question, says 

 that the conclusion which best agrees with the fact of the horns 

 having been so immensely, yet not fixedly, developed — as " shown 



