THYSANURA. 



25 



These little creatures are in several genera covered with 

 scales of various forms and sizes, generally colourless, 

 but sometimes beautifully 

 iridescent, as in the genus 

 Lepidocyrtus. Th«se scales 

 are favourite microscopic 

 objects. Besides scales, hairs 

 of various forms clothe the 

 bodies of these little insects. 

 The young are hatched ap- 

 parently within a period of 

 from six to ten days, the 

 larvse are white and very 

 active in their movements ; 

 I have seen hundreds of 

 them under rotten bark in 

 damp places. The Collembola 

 undergo no metamorphosis. 

 The young differ from the 

 adults merely in being 

 shorter and thicker, and 

 having the spring-tail less 

 developed ; after moulting 

 twice the white larval body 

 becomes of the same colour 

 as that of the adult, purplish 

 and translucent. 



The Thysanura are much 

 less numerously represented 

 both in species and indi- 

 viduals than the Collembola ; the body consists of the 

 head, three thoracic and ten well-marked abdominal 



