NEUKOPTERA. 



219 



CC. Mouth not prolonged into a rostrum. 

 BB. Posterior wings with a folded anal space.* 

 C. Wings reticulate. Prothorax large. 

 CC. Wings with rather few transverse veins. 



AA. Wingless, or with rudimentary wings. 

 B. Mouth prolonged into a rostrum. 

 BB. Mouth not prolonged into a rostrum. 



2. Hemerobiad.i.. 



1. Si ALU). E. 

 Prothorax small. 



4. Phryganeid 1 



3. Panoki'id.e. 

 4. Phryganeid.*. 



Family I. — SlALin.E.f 

 {The Dobson et a I.) 



There is no common name by which the members of this family 

 as a whole are known. The}' are, however, easily recognized. 

 Although the typical genus, Sialis, 

 includes insects of moderate size, 

 our most common forms are large. 

 All are characterized by having the 

 second pair of wings with a folded 

 anal space, and by having a large 

 prothorax. This segment is either 

 quadrangular or cylindrical and long 



The larvae of all of the forms 

 occurring in the Eastern United 

 States are aquatic, living chiefly 

 under stones in the bed of swiftly- 

 flowing streams. They are carniv- 

 orous. 



This family is represented in our 

 fauna by four genera. These can 

 be separated by the following table : 



A. Wings without pterostigma ; prothorax 

 quadrangular. 

 B. No ocelli. Sevlis. 



BB. With three ocelli. 



C. Latero-caudal angles of head un- 

 armed. Transverse veins of wings 

 slender. Ch ^uliodes. 



CC. Latero-caudal angles of head with a sharp tooth. Transverse veins of 

 wings Stout. CORYDAl IS. 



AA. Wings with pterostigma ; prothorax cylindrical and long. R.APHIDIA. 



Fig. 190. — Corydalis cornuta, adult. 



* The anal space is absent in a few Phryganeidse. 

 f Sialidse, Slalis : sialon{cria\ov), saliva. 



