AQUATIC INSECTS 



935 



3 (2) The median vein but once forked; the branches of vein Cui all simple. 



Climacia. 



4 (i) Veins of the wing disc extending outward in straighter lines, forks 



fewer and less symmetrical; antennae cylindric serrate, or 

 pectinate Family Sialididae . . 5 



5 (6) Fourth segment of the tarsus bilobed; posterior branch of the radial 



sector forked. No ocelli Sialis. 



Fig. 1390. Fore wings of two neuropterous insects, Sialis (above) and Climacia (below). A, humeral 

 cross-vein; sU stigma; designations of principal veins as in Fig 1386. 



6 (5) Fourth segment of the tarsus simple, cylindric; posterior branch of the 



radial sector simple. Three ocelli 7 



7 (8) Hind angles of the head rounded; the median vein two-branched; 



antennae with segments enlarged distally. . . ChauUodes. 



8 (7) Hind angles of the head bearing a sharp angulation or tooth; median 



vein three-branched; segments of the antennae cylindric. 



Corydalis. 



1(4) 

 2(3) 



3(2) 



4(1) 

 S(6) 



Larvae 



Mouth parts adapted for piercing and sucking, prolonged to half the 

 length of the body; Hving on fresh -water sponges. ... 2 



Setae on the dorsum of the thorax pedunculate (i.e., the setigerous 

 tubercles elevated considerably above the level of the integ- 

 ument) ; the outer covering of the pupal case spun by the 

 larva is of a beautiful hexagonal mesh Climacia. 



Thoracic setae sessile; the outer covering of the pupal case is close woven. 



Sisyra. 



Mouth parts adapted for biting 5 



The last abdominal segment produced in a long, median, laterally fringed 

 tail-like process; a pair of lateral filaments on abdominal 

 segments 1-7 Sialis, 



