(_Erebiola butleri_, Fereday, Trans. N. Z. Inst. xii. 264; Catalogue of N. Z. Butterflies, 19.)
(Plate XI., fig. 11 [M], 12 [F], 13 under side.)
This interesting butterfly was described from three dilapidated specimens captured by Mr. J. D. Enys at Whitcombe's Pass, Canterbury, on March 8, 1879, at about 4,000 feet above the sea-level. From that time I believe no other specimens had been found until January, 1894, when I took quite a large number on the Humboldt Range, at the head of Lake Wakatipu, at elevations ranging from 4,000 to 5,000 feet above the sea-level.
The expansion of the wings of the male is 1-5/8 inches, of the female 1½ inches. _On the upper side all the wings of the male are smoky-brown; the fore-wings have a large black ocellus near the apex, enclosing two white dots, followed by a smaller ocellus towards the dorsum; the hind-wings have three black spots near the termen, sometimes enclosing white dots._ Occasionally these ocelli are surrounded by a patch of deep reddish-brown. The female is much paler, with large patches of yellowish-brown surrounding the ocelli. On the under side the fore-wings of the male are smoky-brown, with an irregular blotch of reddish-brown near the apex, surrounding a small white-centred black ocellus. _The hind-wings are dark reddish-brown, with several conspicuous black-edged silvery markings, and four yellowish-red spots near the termen._ The under side of the female is very much paler.
This butterfly varies considerably on the upper side in the number and size of the ocelli, and in the extent of the reddish-brown markings which surround them; on the under side the silvery spots on the hind-wings are also variable.
The perfect insect has been taken in January and March. It evidently frequents mountains in the South Island, at elevations of about 4,000 feet, but does not appear to be generally distributed in such localities. It seldom settles on the shingle, mostly resting on the snow grass, on which its larva probably feeds. It is a smaller insect than _E. pluto_, and flies much more feebly. These characteristics will at once enable the collector to distinguish it from _E. pluto_ when on the wing.
Immediately a cloud obscures the sun these butterflies retreat into the tufts of the snow grass, remaining closely hidden there until the sun shines out again. This circumstance makes the capture of the insect, even in a favourable locality, a matter of considerable uncertainty, as bright sunshine is more often the exception than the rule on the summits of high mountains.