268 NATURAL HISTORY OF AQUATIC INSEJTS CH. \ 



the Insect is at rest. In this position the upf er wings jj 

 are nearly flat above, then they bend at an angle and \ 

 slope downwards. These two upper wings are mode- | 

 rately transparent, but appear opaque when they \ 

 overlie the others. It is their opacity which causes 

 them to resemble Butterflies' wings, but on close 

 examination we see that they have none of the scales | 

 which are characteristic of the wings of Lepidop- 

 tera [but are clothed with hairs]. The lower wings 

 are very transparent [and usually folded fan-wise] ; 

 they consist of a colourless or slightly bluish gauzy | 

 membrane. The fly immediately after emergence, | 

 and for some days subsequently, has a greenish tint ; | 

 then it gradually turns dark. The six legs are long. It 

 but the fly does not stand high above the surface on J 

 which it rests. The antennae are very long, longer '\ 

 than the body, gradually tapering, and of many -j 

 joints. The eyes are compound, like those of other 'S 

 Flies and Butterflies. The mouth bears implements |i 

 very unlike those of the larva or pupa. There are li 

 [no mandibles, but] four palps, two above and two k 

 below, besides a very small proboscis [labium .' The 

 tarsi are five-jointed]." 



The eggs of Caddis-flies are laid in water or on 

 water-plants, or on trees overhanging a stream, or 

 sometimes far from water.^ They are often of green 

 colour, and are laid many together in a mucilage 

 which swells out as soon as it comes in contact with 

 vvater, forming a cylindrical egg-rope, or in some 

 cases a flat disc. As soon as the larv.x are hatched, 



^ iMcLachlan, Enloin. Month. Majr., Vol. XVI., p. 135 (1878). 



