202 EXOTIC NEUROPTERA. 



Subfamily Perlinae may be divided into two tribes as 



follows : 



Median vein united to radius near base ; anal cell with one branched 

 vein Chloroperlini. 



Median vein not united to radius near base, but running closely paral- 

 lel thereto; anal cell with two veins Perlini. 



The Chloroperlini include three genera, Chloroperla and 

 Alloperla in which the last joint of the maxillary palpus is 

 very minute, and Paraperla in which this joint is well devel- 

 oped. Paraperla also has a series of cubital cross-veins in 

 the hind wings. In venation this tribe is remarkably similar 

 to the Nemourini, but differ by well developed setae and the 

 retracted clypeus. 



The Perlini includes many genera, most of which I have 

 tabulated in my tables of American Perlidae or are given by 

 Enderlein (Zool. Anzeiger, xxxiv, p. 388, 1909). I cannot 

 consider the number of ocelli as of importance in grouping 

 genera, since one of the two ocelli genera — Hemacroneuria, 

 is evidently more related to Acroneuria than to Neoperla. 

 The genus Ochthopetina made for Old World Neoperlas is 

 very doubtfully distinct from Neoperla. Macrogynopiax dif- 

 fers from Neoperla only in the female genitalia. Cryptoperla 

 differs from Neoperla in the hairy eyes and frontal ridge of 

 head. Niponiella I would consider as Acroneuria, Dictyo- 

 genus as Isogenus, and Dictyopterygella as a Perlodes. The 

 several divisions of Perlodes and Isoge7ius made by Klapalek 

 are hardly more than subgenera, and mostly based on geni- 

 tal characters. Tropidogonopl ax is about the same as Och- 

 thopetina and Tavanita a synonym of Ochthopetina. 



Subfamily Pteronarcinae may be divided into three tribes 

 as follows : 



Anterior coxae more approximate than the others ; many costal cross- 

 veins ; no cross-veins in the cubito-anal space of the fore- 

 wings Pteronarcini. 



Anterior coxae widely separated ; no series of cross-veins in cubito- 

 anal space; few costal cross-veins Leptoperlini. 



Anterior coxae widely separated ; a series of cross-veins in the cubito- 

 anal space of fore-wings Eusthenini. 



The Eusthenini includes three genera ; Ste7ioperla, green 



