BY R. J. TILLTARD. 411 



pale annuli. Cerci 13.5 mm. long, medium brown, with from 45 to 50 segments.* 

 Genitalia as shown in Text-fig. 1. 



Wings shining hyaline, suffused with rich umber brown basally and along 

 costa to beyond pterostigma, as shown in Plate xxxiv., fig. 1. This colour is 

 darkest on the pterostigma of forewing, fairly dark on the anal area of the 



Text-ti^. 2. Tasiiianophlebia lacus/ris, n.g. et sp,, wing-venation of 5 imago. (x7i). 



same wing and on costa of Iiindwing, and paler on the rest of the suffused area. 

 Veins dark brown. Venation as shown in Text-fig. 2. 



?, Imago: Total length, 13; forewing, 11.5; hindwing, 5.8; expanse of 

 wings, 25 mm. 



Similar to male, except that the foreleg's are only 5 mm. long, the eyes 

 smaller, the abdomen rather duller, with less conspicuous annuli separating the 

 segments, and the wings somewhat narrower and almost totally hyaline, being 

 only suffused with brown on the pterostigma and at their bases, as shown in 

 Plate xxxiv., fig. 2. 



S, Subimago : Differs from the imago in being a somewhat smaller and 

 slenderer insect, the body colouring duller, the forelegs and cerci much shorter, 

 the wing's narrower, not hyaline, but clouded with pale dull greyish; pterostigma 

 and all tlie veins dark gi'e\'isb; a toucli of brown at bases of wings. (Plate xxxiv., 

 fig. 3.). 



?, Subimago : Closely resembling the male subimago, but having tlie 

 abdomen a duller greyish brown, and the lirown at the base of the wings more 

 conspicuou.sly present. (Plate xxxiv., fig. 4). 



Hob.— Lake Lilla, 3200 feet, near Cradle Mountain, N.W. Tasmania. 



Types. Holotype c? imago and allotype ? imago, reared from subimagines, 

 Jan. 23rd, 1917. Also c? and ? subimagines, taken Jan. 21st, 1917, at same time 

 as imaginal types. All these in tlie Tillyard Collection, Cawthron Institute, 

 Nelson,' N.Z. 



The discovery of this insect throws some interesting light upon the close 

 relationships existing between the Australian and New Zealand May-fly Fauna. 

 New Zealand, witli its abundant, rapid and ever-flowing rivers, and its numerous 

 lakes, is a paradise for these insects. Australia, on the other hand, with its 



* The cerci of the type male imago were accidently broken off before the photographs 

 ■were taken for Plate xxxiv. 



