44 NEW ZEALAND NEUROPTEBA. 



shining. The cross-veins? on the costa near the base of the wing are very 

 thick, especially in the female. The costa of the fore-wing is shaded with 

 brown near the apex. The length of the body is about J inch. In this 

 species none of the abdominal segments are produced into lateral flanges. 



The nymph inhabits the rapid rocky stream which 

 flows into the Upper Wainui-o-mata Eiver on its eastern 

 side above the reservoir, locally known as George's 

 Creek.* It is not very active, and, owing to its large 

 size, is easily seen and captured by means of the hand 

 only. Hence its speedy extinction by trout appears 

 inevitable ; and it is noteworthy that in the lower por- 

 tions of the Wainui-o-mata, where trout have been abun- 

 dant for many years, none of these insects occur. 



The length of the full-grown larva, including the terminal appendages, 

 is nearly 1J inches. The head is rather small, with the eyes black and very 

 prominent. The thorax is rather narrow with the wing-pads small. The 

 abdomen is broad ; the edges of each segment are produced into distinct 

 flanges, which project backwards like teeth. There are six pairs of gills, 

 which do not ordinarily extend beyond the sides of the abdomen, but in the 

 living insect are usually held somewhat above the back. (See Plate XL, 

 fig. 15, single gill much magnified.) They are almost continuously in 

 motion. A very pronounced row of projections exists on the dorsal surface 

 of the abdomen, which forms a very characteristic, serrated, horny crest. 

 The tails are stout and strongly fringed ; the ends of the two outer tails are 

 often curved ; the central tail is straight and slightly shorter than the other 

 two. The legs are rather short and moderately slender. The general 

 colour of the larva is dull slaty brown marked with black, and sometimes 

 slightly tinged with dull reddish. Younger larvae are very much paler, with 

 the black markings darker ; occasionally they have in addition several 

 irregular white patches on the body. 



The food of this insect appears to consist of vegetable 

 matter, probably contained in the earthy matter com- 

 posing the bed of the stream. It is found in the streams 

 throughout the entire year. Very small specimens are 

 most abundant in autumn and winter, the nymph be- 

 coming full grown about November. At this season the 

 larva leaves the water and ascends a dry boulder, generally 

 near the middle of the stream. The May-fly then escapes 

 through a rent in the back of the nymph. 



The sub-imago of this species is extremely handsome 

 when alive, a dried specimen giving but a feeble idea of 

 its real appearance. The general colour of the wings is 

 deep purplish-black, beautifully mottled with darker 

 black. All the appendages are, as usual, shorter and 

 stouter than in the imago. The insect remains in the 

 sub-imago state for three or four days. During a con- 



* I have also found this insect in the Mangatariri Eiver, at the foot of 

 Mount Holdsworth. 



