42 NEW ZEALAND NEUROPTEBA. 



of the other May-flies, and its beautiful sub-imago is also 

 more frequently seen by casual observers. The imago is 

 seldom seen, and I have not yet observed it flying at 

 night. 



This May-fly is not nearly so common as Ichthybotus 

 hudsoni, although its nymphs are much more frequently 

 observed, probably owing to their inhabiting the clear 

 portions of the streams, instead of secreting themselves in 

 burrows in the banks. 



Genus ONISCIGASTEK, McLachlan (1873). 



Imago. — Legs all functional ; hind tibite much shorter than the tarsus ; 

 claws dissimilar in each tarsus. Hind-wings well developed, obtusely sub- 

 ovate, the dilatation of the marginal area obtuse in front ; axillar region 

 well developed, largely occupied by numerous long anastomosing nervules. 

 from the inner margin. Median caudal seta shorter than the outer pair. 

 Abdomen very robust. 



Distribution. — New Zealand. 



This is a very interesting genus, and is probably 

 rapidly approaching extinction. 



ONISCIGASTEK WAKEF1ELDI. 



Oniscigaster wakefieldi, McLachlan, Ent. Mo. Mag., 

 vol. 10, p. 108 (1873) • Journ. Linn. Soc, vol. 12, p. 139, 

 pi. 5, figs. 1-5 ; Eaton, Trans. Linn. Soc, 2nd series,. 

 Zool., vol. hi., p. 224, pi. 21, fig. 3(3 (details imago) and 

 pi. li. (nymph) ; Sharp, in Cambridge Natural History,, 

 vol. v., Insects, p. 442, fig. 284; Hutton, Trans. N. Z. 

 Inst., xxxi., 218; Eaton, Trans. Ent. Soc. Lond., 1899, 

 292. 



This remarkable species has occurred in the Canter- 

 bury and Nelson districts, but appears now to be an 

 extremely rare insect. 



The expansion of the wings of the male is about 1£ inches, of the female 

 If inches. " The general colour of the imago is dark brown, rather lighter 

 in the male. The wings are vitreous, faintly tinged with light brown ; 

 nervules dark edged. The legs are light brown, banded with darker. 

 Length, 10-21 mm. ; wing, <s 1(5 mm., ? 19-21 mm. ; setae, 17 and 5 mm. 

 Expanse of the wings, $ 35 mm., ? 40 mm. 



" The sub-imago has the body greyish. The wings are sub-opaque, smoky 

 grey ; nervules of the anterior portion of the fore-wing broadly edged with 

 dark brown. Length of the setae, 13 and 7 mm." (Hutton). 



" In this species the female has three dorsal segments, viz., the seventh 

 to ninth, sinuate somewhat deeply on each side at the posterior margin, and 

 dilated laterally into thin expansions, that are rounded off to the base in 

 front and acute behind, so as to form broad serratures like coxse of Oniscus 

 murarius. Above these the back, in dried specimens, is somewhat fornicate, 

 with a median longitudinal depression. The first and second of the lateral 



