THE BOMBYCINA. 309 



possess another common character of still greater 

 importance. This consists in the rudimentary con- 

 dition of the parts of the mouth_, which are, in- 

 deed, so much reduced, that they are generally de- 

 scribed as non-existent. The antennse are short, iti 

 no case surpassing the thorax in length, whilst in the 

 Ghost Moth they are but little longer than the head. 

 In this Moth, too, they form simple filiform organs, 

 but in the others they are furnished with delicate 

 lateral filaments, which give them the appearance of 

 small feathers, especially in the males. 



Several of these characters are common to a con- 

 siderable number of other Moths, forming the tribe of 

 the BoMBYCiNA, of which the common Silkworm Moth 

 {Bomhyx Mori) is one of the best-known species. In 

 all these insects we find the trunk very small or ru- 

 dimentary, the body thick and obtuse at the extre- 

 mity, and the antennse short, and usually pectinated. 

 They have no ocelli on the crown of the head, and 

 their hinder legs are not distinctly longer than the 

 intermediate pair. In their habits, however, the ma- 

 jority of these insects differ considerably from those 

 to which I have just referred ; for, instead of leading 

 a subterranean existence and feeding on the roots of 

 plants, or living concealed in the interior of the trunks 

 of trees and devouring their solid wood, the larvse of 

 most of the Bombycina feed upon the leaves of plants; 

 and although a few of them bury themselves in the 

 ground to undergo their transformations, the greater 

 number pass their whole existence in the open air. The 

 caterpillars of several species are social in their habits, 

 living in great numbers together in a silken nest, in 

 which they shelter themselves during the night, or in 

 rainy weather, going al^road during the day to feed 



p5 



