32 FAUNA HAWAIIENSIS 



for their reception. The simpler forms of this genus are very similar to the well-known 

 genus Micromus, but the more remarkable species have the wing-contour of Drepa- 

 nopteryx, and bear to Micromus a relation very similar to that which Drepanopteryx 

 bears to Megalonius or Hemerobius. Between the extreme forms of Nesomicromus 

 species are found in quite intermediate conditions, so that one is compelled to treat the 

 whole series of species as forming but a single genus, and their relationship is strongly 

 evidenced by the apical abdominal appendices of the tt, which though differing in 

 detail in many species, nevertheless possess notable peculiarities common to all. 



Allied to Nesomicromus, and no doubt evolved within the islands from some such 

 form, are the other two genera, Pseudopsectra and Nesothauma, each with but one 

 species at present known. The former is in most respects intermediate between the 

 latter and Nesomicromus. Both these insects, but especially the Nesothauma, have 

 claim to be considered amongst the most remarkable of all known species oi Neuroptera. 

 Nesothauma has no trace of posterior wings and the front pair are almost of the 

 consistency of the elytra of a Coleopterous insect. Pseudopsectra is likewise incapable 

 of flight, but the front pair of wings are less abnormal, and the posterior pair are 

 represented by small lobes. Although reminding one of the anomalous and rare genus 

 Psectra, Psetidopsectra is, without doubt, not related in any way to that genus. The $ 

 characters of both Pseudopsectra and Nesothatima are formed entirely on a similar plan 

 to those of Nesomicromus. The two insects included in these abnormal genera are 

 very local and rare, and both frequent the same locality, Haleakala on Maui, where 

 they are found at an elevation of five or six thousand feet above sea-level. 



As above mentioned the single species of Chrysopa is almost certainly foreign, but 

 another genus, Anomalochrysa, not known from elsewhere, includes no less than 29 

 species. These species form a most interesting series, but are excessively difficult to 

 differentiate, owing to the great variability in colour of many of them, and the instability 

 of the characters afforded by the nervuration. Here again the terminal segments of the 

 ^ afford great help in many instances, and on these characters there would appear to be 

 two good genera, but the females of the two sections appear to present no points for 

 generic division, at least in dried examples, the distortion of the body after death being 

 much greater in this sex than in the ^. 



The species of Hemerobiidae have in general a much more restricted range than 

 have the indigenous Agrionidae of the Odonata. Excluding the single Megalomus and 

 Chrysopa as probably foreign, of the genus Nesomicromus 1 5 out of the 1 9 are restricted 

 each one to a single island, the remaining four being widely distributed insects, Hawaii 

 and Maui each having four species peculiar, while the latter likewise has also its 

 peculiar genera Psetidopsectra and Nesothau7iia. The species of Anomalochrysa are 

 even more localized, two only of the 29 occurring on more than one of the islands. In 

 this genus the island of Hawaii is extraordinarily rich, since it has 12 species peculiar to 

 itself, and both of the two more widely distributed species are also found there. The 



