Lillie. — On New Zealand Ephenieridae. 149 



Art. XI. — Notes on New Zealand Ephemeridae. 



By C. 0. Lillie, M.A., B.Sc. 



[Read before the Otago Institute, 9th October, 1900.'] 



Plate VII. 



Nymph unknown. 



The accompanying plate shows drawings of an Ephemerid 

 nymph which is to be found in a few streams about Dunedin. 

 The colour is from reddish-brown in the younger stages to 

 brownish-black in the full-grown nymph. The surface is 

 thickly beset with stiff bristles and spines. The legs are 

 markedly flexed, but are shown straightened in the figure. 

 The wing-cases are very prominent, and project from the 

 body. 



The nymph is found on stones in swiftly-running water. 

 It swims clumsily by flexing and extending the body, and 

 seems of sluggish habit. 



All my attempts to rear it have been unsuccessful. 



Note to Art. XX., Vol. XXXI., Trans. N.Z. Inst. 



Specimens of the nymph, subimago, and imago of the in- 

 sect identified as Atalophlebia scita were forwarded to the Bev. 

 A. E. Eaton, author of the monograph on the EphemeridcB. 

 Mr. Eaton places it in a new genus, Deleatidium, and names 

 the species Deleatidium HUH, and gives the following descrip- 

 tion in his " Annotated List of the New Zealand Ephemeridcs " 

 (Art. xi., Trans. Ent. Soc. London, 1899, part iii.) : — 



"Deleatidium. Eaton. 



" Distinguished as a genus from Leptophlebia by the 

 <y imago having genitalia conformable in pattern to those of 

 an Atalophlebia, and by the nymph having tracheal branchiae 

 in the form of single, ovate, acute, penniveined foliaceous 

 lamellae. The tracheal branchiae of the first abdominal seg- 

 ment are reniform, unlike those of the other segments. The 

 •cross-veinlets of the fore wing in the typical species are in 

 two of the specimens widely spaced in places, after the man- 

 ner of those of the species of Atalophlebia here illustrated, but 

 in the other specimens of the same and of the other sex the 

 blanks are less noticeable or are filled up. The name in 

 Greek signifies ' a little bait.' 



