40 NEW ZEALAND NEUBOPTERA. 



The duration of the sub-imago state of Ameletas ornatus 

 is about two days. When at large the perfect insect so 

 closely resembles C. humeralis that it is of course difficult 

 to estimate their relative abundance, or to describe their 

 individual habits. The present species is not, however, 

 so common as C. humeralis, although, judging from the 

 number of its larval skins which we see on the stones, it 

 must still be an abundant insect in many localities. 



AMELETUS PERSCITUS. 



Ameletus perscitus, Eaton, Trans. Ent. Soc. Lond., 

 1899, 291. 



<Plate V., rig. 1 $ , 2 nymph magnified, 3 2 sub-imago.) 



This very pretty May-fly is fairly common in the 

 neighbourhood of Wellington. It has not at present 

 been recorded from any other locality. 



The expansion of the wings is about 1$ inches, and the length of the 

 body § inch. The body is pale ochreous, with a series of pale brown mark- 

 ings and black dots on the back. The wings are bright clear yellow and 

 very shining. The central tail is very short. In the male the two other 

 tails are half as long again as the body, but in the female they are consider- 

 ably shorter. 



The larva of this insect is found under stones in rapid 

 streams throughout the entire year. It is generally full 

 grown about the end of December, but some specimens 

 do not reach maturity until the beginning of March. 

 This larva is a very rapid swimmer, and cannot readily 

 be captured without the aid of a small net. Unlike most 

 May-fly nymphs it is carnivorous, and feeds on the larvae 

 of various smaller species (Atalophebia and Deleatidium), 

 which it captures by means of its powerful jaws. 



The length of the mature larva is rather less than 1 inch. The head is 

 nearly round and very large. The eyes and ocelli are black and very con- 

 spicuous. The organs of the mouth are well developed ; the mandibles and 

 maxillre are long, slender, and sickle-shaped. The thorax is rather long 

 and narrow, and the wing-pads do not project beyond the parallel sides of 

 the thorax. The abdomen is furnished with seven pairs of very large leaf- 

 like gills (see Plate XL, tig. 16), which are frequently simultaneously vibrated 

 by the larva. There are three stout tails at the end of the body, each of 

 which is strongly fringed with long hair. The legs are rather short and 

 slender, pale yellowish-brown striped with black. The general colour of the 

 larva is dull greenish-ochreous, with dark brown or blackish markings. 

 Younger specimens are usually much paler and yellower in colour. 



This larva may be at once recognised by its very large 

 head and conspicuous eyes, no other May-fly nymph with 



