1886.] 263 [Hagen. 



Very similar to N. angalata in color and shape, but smaller. 

 The eyes of the male are smaller, more distant, about twice their 

 diameter, the vertex less deepened ; head fulvous, more yellowish 

 below; grooves behind the base of antenna dark brown, both 

 grooves separated by a less sharp carina ; the transverse line of 

 the occiput not visible from above ; antennae fulvous, base yellow- 

 ish, longer than the body with more than sixty joints ; the elon- 

 gate fovea on each side just on the apex of the front and the base 

 of the epistoma, with a yellow, bijointed, very thin cylindrical 

 palpus ; this palpus is present on each fovea, standing in the lower 

 end of it vertically. I do not know if it is evaginated out of the 

 fovea, and I must say that among forty specimens before me, this 

 andN. filipennis are the only ones showing this palpus ; this fovea is 

 present in other Hemerobina, very large in Palpares ; also in Pseu- 

 doneuroptera in Odonata. Its development in Corydalis is very 

 peculiar ; it forms in the imago a complete perforation and was 

 first mentioned by Dr. S. S. Haldeman in Proc. Acad. N. Sc, 

 Philad., 1846, n, 192, and later in the monograph p. 160. " They 

 are present in both sexes, and are sufficiently large at the narrowest 

 part to admit a bristle, and from this point they enlarge upwards 

 and downwards. They are situated at the internal extremity of 

 a transverse impression above, and in the angle of a curved fissure 

 beneath, which separates the post-mentum from the cranium. 

 There is no interruption in the solid exterior of the head as it 

 passes through and lines this perforation, so that thus far it has 

 afforded no additional information as to the functions of the an- 

 tennae. (The perforation in Corydalis is at the anterior base of 

 each antenna). " M'Lachlan has mentioned it in Stenotaenia, 1. c. 

 p. 376. 



As far as I am able to state now, this fovea belongs really to 

 the base of the epistoma and is prolonged externally on the ad- 

 jacent apex of the front or beneath its anterior margin and covered 

 by it, as in Odonata. I believe I remember a suggestion that it is 

 connected with one of the senses, but I am now unable to find 

 where or by whom. The presence therein of a kind of palpus (I 

 do not know how to call it otherwise) is so extraordinary, that I 

 would not have mentioned this fact, if I had not ascertained it by 

 the most careful examination with the compound microscope, and if 

 it were not present on both sides exactly in the same manner. 



