3/6 LEPIDOPTERA 



CHAP. 



genera, and none of them have many species. The Mustiliidae 

 of some entomologists are included here. Like the Saturniidae, 

 the Bombycidae are destitute of proboscis and of frenulum to the 

 wings, but they possess two or three internal nervures on the 

 hind wing instead of the single one existing in Saturniidae. 



Fam. 1. Eupterotidae (Striphnopterygidae of Aurivillius).- 

 This family has only recently been separated from Lasiocampidae ; 

 its members, however, possess a frenulum ; while none is present 

 in the larger family mentioned. Its limits are still uncertain, 

 but it includes several extremely interesting forms. The larvae 

 of the European processionary moth, Cn<'f/ii><'<///ipa2}rocessionea,&Te 

 social in habits ; they sometimes occur in very large numbers, and 

 march in columns of peculiar form, each band being headed by a 

 leader in front, and the column gradually becoming broader. It 

 is thought that the leader spins a thread as he goes on, and that 

 the lateral leaders of the succeeding files fasten the threads they 

 spin to that of the first individual, and in this way all are 

 brought into unison. The hairs of these caterpillars are abun- 

 dant, and produce great irritation to the skin and mucous mem- 

 brane of any one unlucky enough to come into too close contact 

 with the creatures. This property is, however, not confined to the 

 hairs of the processionary moths, but is shared to a greater or 

 less extent by the hairs of various other caterpillars of this 

 division of Lepidoptera. In some cases the irritation is believed 

 to be due to the form of the hair or spine, which may be barbed 

 or otherwise peculiar in form. It is also thought that in some 

 cases a poisonous liquid is contained in the spine. 



The larvae of other forms have the habit of forming dense 

 webs, more or less baglike, for common habitation by a great 

 number of caterpillars, and they afterwards spin their cocoons 

 inside these receptacles. This has been ascertained to occur in 

 the case of several species of the genus Aiutplie, as has been 

 described and illustrated by Dr. Fischer, 1 Lord Walsiugham, 2 and 

 Dr. Holland. 3 The structures are said to be conspicuous objects 

 on trees in some parts of Africa. The common dwelling of this 

 kind formed by the caterpillars otHypsoidcs radama in Madagascar 

 is said to be several feet in length ; but the structures of most 

 of the other species are of much smaller size. 



1 Iln-Iiii. cnt. Zeitschr. xxvii. 1883. p. 9. 

 2 7>. Linn. Soc. ser. 2. ii. 1885, \>. 421. 3 Psyche, vi. 1893, p. 385. 



