38 NEW ZEALAND NEUBOPTEBA. 



the late afternoon, generally between five and seven 

 o'clock. Each individual rises and falls in its flight, 

 after the usual manner of May-flies, and in favourable 

 localities the insects are often seen in very great numbers. 

 It is consequently an important species to the angler, as 

 its nymph must furnish an abundant food supply for trout 

 throughout the entire year, the perfect flies also con- 

 tributing a liberal supply of food during the three 

 months they are more or less abundant. 



Genus AMELETUS, Eaton (1899). 



"Hind-tibia sub-equal in length to (hardly if at all longer than) the 

 tarsus ; basal joint in this tarsus measured along the sole, equal to the next 

 joint, and also dorsally sub-equal thereto, the breadth of the colouring of the 

 tibio-tarsal boundary making it difficult to ascertain their exact proportions 

 dorsally. In every tarsus the outer or posterior claw is narrow and hooked, 

 the inner broad and obtuse, costal shoulder of the hind-wing obtuse." * 



AMELETUS ORNATUS. 



Chirotonetes (/) ornatus, Eaton, Trans. Linn. Soc, 

 2nd series, Zoology, vol. hi., pp. 208 and 321, pi. 19, 

 fig. 33c (1888) ; Hutton, Trans. N. Z. Inst., xxxi., p. 217. 

 Ameletus ornatus, Eaton, Trans. Ent. Soc. Lond., 1899, 

 p. 291. 



(Plate VI., fig. 1 c? subimago, 2 ? ditto, 3 nymph 

 magnified.) 



This insect has been found at various localities in 

 the vicinity of Wellington. It is very common in the 

 Wainui-o-mata Valley. 



The expansion of the wings of the male is 1 inch, of the female 1J inches. 

 In general appearance the imago of this May-fly very closely resembles that 

 of Coloburiscits humeralis, but the brown patch on the costa near the apex 

 is not nearly so pronounced in the present insect, and it is mainly formed 

 by a darkening of the veins only, the membrane of the wing being but 

 slightly shaded with brown. The femur of the anterior legs in the male is- 

 also considerably longer than it is in the corresponding sex of C. humeralis. 



The larva of this insect inhabits only swift clear 

 streams, and frequents the most rapid portions of these, 

 where the current dashes over a stony bottom. It is 

 extremely active, and swims with great rapidity, hence 

 being very difficult to capture. Its colouring is also pro- 

 tective when it is resting on the stones, which is its 



* Trans. Ent. Soc. Lond., 1899, 290. 



