NEUEOPTERA— PLANIPENNIA— HEMEROBINA. 169 



primary sector. In Nothoclirysa it runs in a perfectly straight course a 

 little below tlie middle of the wing, but higher than in Chrysopa, directed 

 toward but not distinctly reaching the middle of the outer half of the lower 

 margin of the wing, and supporting the lower proximal end of one trans- 

 verse series of gradate veinlets between it and the primary sector. In Trl- 

 bochrysa it runs in a decidedly zigzag course, in the same general direction 

 as in Nothochrysa in its proximal half, and then shifts suddenly to a higher 

 level and follows thereafter a zigzag direction nearly parallel to tlie costa, 

 through the very middle of the wing, joining, that is, the transverse series 

 of gradate veinlets and making them a part of itself. Tribochrysa further 

 diifers from Nothochrysa and agrees with Palreochrysa in the slender number 

 of secondary sectors or oblique cross-veias, so that the cells are larger and 

 less elongated than in Nothochrysa and Chrysopa, standing thus at a wider 

 distance from Hemerobius. The result of this movement of the first cubital 

 vein is usually a striking inequality of. the cells on either side of it, in con- 

 trast to their uniformity in Palseochrysa. There is here, therefore, as in 

 Palseochrysa, no transverse series of gradate veinlets in the proper sense, as 

 both series are directly united with the two cubital veins. A somewhat 

 similar arrangement may be seen in Nothochrysa fulviceps, although that 

 species differs from these more widely than most of its allies in the nuilti- 

 plicity of its secondary sectors. The same double cubital cell occurs below 

 the second subradial cell as is found in Nothochrysa and Palseochrysa 



The species placed here seem to fall into two groups, one of the species 

 differing from the others in being of a considerably larger size, having its 

 first cubital vein originate directly from the radius, the proximal cells 

 which lie above it less elongated than in the other species, and the upper 

 (double) cubital cell quadrangular. 



TabJe of the species of Trihochrysa. 



Large species. First cubital vein arising directly from the radius; first transverse vein connecting 

 radius and first cubital vein lying in direct continuation of the cross- vein closing the proiimal 

 end of the double cubital cell, makiug the upper, as well as the lower, cell quadrangular. 



1. T. vetmcula. 



Smaller species. First cubital vein arising from a basal cross-vein uniting the radius and second 



cnbital vein ; first transverse vein connecting radius and first cnliital vein striking the upper 



margin of the double cubital cell, making the upper cell pentagonal, while the lower remains 



quadrangular. 



Elongated proximal cells between the main sector of the radius and the first cubital vein, four in 



number, followed by half a dozen cells of subequal diameters 2. T. inequalis. 



Elongated proximals cells, as above, three in number, followed by five cells of subequal diameters. 



3. T.firmata. 



