Campbell. — Notes on the Bltpharoceridae of New Zealand. 263 



choose between them, both being uniformly dark-coloured. Ventrally, 

 however, the Ohakune larvae are lighter in colour. The gill-filaments 

 increase in number with the age of the larvae, stages with 2, 4, and 7 

 filaments having been observed. Edwards (1915, p. 208) has noted a 

 similar increase in Elporia barnardi. 



Notes on Eggs, Larvae, and Pupae. 

 Eggs. (Figs. 84 and 85.) 



Slide specimens of the adult female C. chiltoni show the elliptical egg, 

 contrasting with the egg of Bibio johannis, which is cylindrical with 

 abruptly rounded ends. The egg-membrane and the granulated contents 

 separate in slide preparations, and the membrane appears covered with 

 round bosses, corresponding to the developing external layer of cells of 

 the egg. Eggs that I have found adhering to the underside of stones in a 

 creek are brown in colour. During the last stages they show distinctly 

 darker on one side. With a good top lighting, low powers show that the dark 

 side is the dorsum of the contained larva. Each segment has 4 spines, 

 and the antennae and the central plate of the cephalon are clearly discerned. 

 The light side shows the 6 circular dark rings of the suckers and the faint 

 outline of the lateral processes. No evidence is available as to how the 



Fig. C. — Blepharocerid eggs. 1. Showing patches of eggs. 



developing larva. 



Magnified to show 



fly places the eggs on the stones beneath the water. Freshly emerged 

 larvae appear to have only the anal set of gills ; the next stage includes 

 the addition of one gill on each side for the other segments, and the total 

 number of gills is reached before the last moult. Spines and gills increase 

 during the moulting stages. Further search has confirmed my opinion in 

 regard to Purau Creek. The Blepharocerid there is C. chiltoni, and after 

 careful search I failed to get a single specimen of turrifer. The flies have 

 a habit of sitting on the stones with the long hind legs touching the 

 margin of the running water. With each increase of the flow of the 

 water the fly will be pushed up about Jin. or more, but each time 

 the fly merely backs down to the original position. It seems probable 

 that the female dives under to lay ; otherwise it seems difficult to 

 account for the eggs adhering in patches, at depths far beyond the reach 

 of the insect. 



