756 STUDIES IN AUSTRALIAN NEUROPTERA, vi,, 



Turning next to the region of the media and cubitus, on the 

 character of wliich Navas attempts to divide the Australian 

 species from the African, as two separate tribes, on the ground 

 that the former have no anastomosis in this region, the condition 

 to be seen in PsychopsU eletjans is shown in Text-fig. 1 and Text- 

 fig. 4, b. In the tracheation, M._, approaches Cu^ very closely for 

 a considerable distance, and then diverges from it again. In the 

 corresponding venation, M2 fuses with Cu^ for this same distance, 

 and the parts of Mg just before the fusion, and of Cuj just after 

 it, are bent so as to appear like oblique cross-veins. It is cleai' 

 that here we have a true anastomosis, comparable with that 

 between Sc and R already mentioned in Osmylidce. But this 

 anastomosis is not a constant character, either for the species 

 elegans or for the genus Psychopsis, as I have noted more fully 

 on p. 761. The type of anastomosis in this region in Psychojysis 

 inimica, in which, usually, Mj just anastomoses with Mo at a 

 point, and Mg in its turn with Cuj, is shown in Text-fig. 4, a. In 

 other species, such as Ps. insolens, there may be, in the majority 

 of specimens, no anastomosis whatever in this region. 



The arrangement of the cross-veins, which are not represented 

 in the precedent tracheation, is of great interest. In Ps. elegans 

 (Text-fig. 1), we note, first of all, the presence of a gradate series 

 closing the disc distally (f/i). This may be termed the diseal 

 gradate series. Internally to this, and crossing the disc not far 

 from its middle, there is another series {g^, which may be called 

 the iiiternal gradate series. These two series will be at once 

 recognised as the homologues of the two gradate series normally 

 present in the wings of (Jhrysopid(e. Besides these, there will be 

 seen a long series of cross-veins connecting the veinlets of the 

 costal space, and extending right from near the base to the apex. 

 This may be termed the costal gradate series (cov). Below the 

 apex, this series is continuous with a gradate series roughly 

 parallel to the discal series, but lying between it and the termen 

 of the wing. This may be called the terminal gradate series {tv). 

 Except for a slight development of costal cross- veins in such 

 genera as Drepanepteryx, the costal gradate series does not appear 



