MANUAL OF NATURAL HISTORY. 219 



5. FAMILY. Lace -Wings (Heinerobiidae). Head 



small; eyes prominent, often of a brilliant 

 metallic lustre ; antennae long, filiform, com- 

 posed of many joints ; first segment of thorax 

 small ; abdomen soft, of moderate length ; 

 wings large, very delicate, posterior pair ra- 

 ther smaller than anterior. 



6. FAMILY. May-Flies (Sialidae). Head moderate, 



transverse ; antennae long, filiform, sometimes 

 pectinated and many jointed ; first segment 

 of thorax as large as the head ; abdomen not 

 long ; anterior wings very large, posterior a 

 little smaller, carried horizontally or deflexed 

 along sides of body, hind-wings folded when 

 at rest. 



7. FAMILY. Water-Moths* (Phryganeidae). Head 



small; eyes prominent; antennae slender, se- 

 taceous or pectinated, generally longer than 

 the body; wings roof-like, membranous, of 

 nearly equal size, nerves simply branching, 

 anterior pair generally pilose, posterior trans- 

 parent and folded when at rest ; abdomen 

 rather soft ; legs long and slender ; tibiae 

 spurred. 



CLEAR-WINGED INSECTS. 



This Order is very extensive, comprising about a 

 fourth of the entire insect race ; its members are 



* Called also "Caddice-Flies." 



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