NEUROPTERA— PLANIPENNIA— HEMEROBINA. 161 



the cubital cells can not be determined in the front wing, but are apparently, 

 as here, pretty large and broad and rarely if ever twice as long as broad, 

 while nearly all the other large cells (especially in the front wings) are very 

 long and slender as in I. tumulata, the transverse veins being few. The 

 marginal veinlets of both wings are simply and widely forked on the lower, 

 and sometimes on the apical, border. 



Length of wings, 10.5'""'; breadth, 2.7""". 



This species is evidently more nearly allied to I. tumulata tlian to any 

 of the others, and differs from it, not only in the points brought out in the 

 description, but also in the closer venation of the margin of the wing. 



Florissant. Two specimens, Nos. 8319, 9391. 



Family HEMEROBINA Hagen. 



The two subfamilies Hemerobidae and Chrysopida; which form this 

 group are oppositely represented in the Tertiaries of the Old and New 

 Worlds. The former are well represented in Europe and poorly represented 

 in this country ; the latter are well furnished with species in this country 

 and are unrepresented in Europe. The figures stand as follows: Hemero- 

 bidse, four genera, six species, Europe, vs. two genera, two species, America; 

 Chrysopidae, none, Europe, vs. two genera, four species, America. Compare 

 this with their present distribution as indicated by Hagen in his Synopsis 

 synonymica (1866) : Hemerobidse, ten genera, forty species, Europe, vs. 

 eight genera, thirty-one species, America; Chrysopidas, two genera, forty- 

 one species, Europe, vs. one genus, thirty-one species, America. Here the 

 relation between America and Europe is almost precisely the same in the 

 two countries, a relation which finds no sort of explanation in the distribu- 

 tion of the two groups in the Tertiaries. (September, 1S83.) 



Subfamily HEMEROBID.^ Stephens. 



Considering tlie abundance of American Tertiary Neuroptera and the 

 considerable number of Hemerobidaj (four genera, six or more species) 

 found in the Tertiary beds of Europe — mostly in amber — it is somewhat 

 surprising to find only a couple of species in our American Tertiaries. One 

 of these, Osmylus, .from Florissant, is also represented in amber and the 

 two species agree together in certain features which distinguish them from 



VOL XIII 11 



