218 NATURAL ARRANGEMENT OP INSECTS. 



longer than the shank, with the first joint scarcely half 

 the length of the last. These characters, joined to the 

 convexity and pubescence of their bodies, seem to afford 

 the best external distinctions of the Melolonthina. 

 Their food consists almost entirely of leaves ; and they 

 occasionally appear, at uncertain intervals, in amazing 

 swarms. It is, perhaps, one of the most widely distri- 

 buted groups of the arboreal beetles ; since we have 

 before us typical species from Africa, India, America, 

 and Australia : they seem, however, to be more abun- 

 dant in temperate than in tropical countries. The only 

 form which we have yet seen, possessing a rudimentary 

 horn on the thorax, is the genus Pachypus of Fabricius, 

 which we have occasionally captured in Sicily : it is, 

 perhaps, by this genus that the Melolonthince are united 

 to the Megasomince. 



(190.) It is a very remarkable circumstance, that a 

 distinguishing feature of the entomology of Southern 

 Africa is the hairy clothing of the majority of its 

 contents. Of this we have a strong exemplification in 

 this family, in Cephafotrichia Kirby, the type of which 

 is Melolontha Alopeoc, in which all parts of the insect, 

 excepting its elytra, are densely covered with very long 

 down. The general aspect of these insects, both in 

 form and colour, is dull and heavy, instanced in the 

 type Melolontha itself. Of course, exceptions occur; 

 and yet, notwithstanding this circumstance, they appear 

 to have a compensation in the great beauty of the elegantly 

 lamellated antennae in the majority of the males. The 

 dilated tarsi are clothed beneath with hair in the genus 

 Geniates, and which is a structure of very rare occurrence 

 in the Petalocera ; it, however, is found only in the male 

 insect. Many HoplicB are beautifully enlivened with 

 delicate metallic tints, arising from their dense clothing 

 of scales ; and the little New Holland DiphucephalfE are 

 equally distinguished for their metallic brilliancy, which, 

 however, is not of so fragile a nature as in the last, 

 it being the integument itself which is thus coloured. 

 The British Serica is very delicate in texture ; and some 



