VI—THE BUTTERFLIES. 31 
We have two species in New Zealand, both confined to 
the South Island. 
EREBIA PLUTO. 
(Hrebia pluto, Fereday, Trans. N.Z. Inst., iv., 217; ib., xii., 
265, pl. ix., 2; Erebia merula, Hewitson, Ent. Mo, Mag., xii., 10 
(1874); Oreina othello, Fereday, Trans. N. Z. Inst., viii., 302, 304, 
pl. ix. (1876); Perenodaimon pluto, Butl., Ent. Mo. Mag., xii., 153 
(1876); Catalogue of N. Z. Butterflies, 10.) 
(Plate V., fig. 132, 309, 29 under side.) 
This fine butterfly has occurred plentifully on many 
mountain-tops in the South Island, from Nelson to Lake 
Wakatipu. It has never been observed in the North Island. 
The expansion of the wings of the male is 13 inches, of the 
female 2 inches. On the upper side all the wings are a very rich 
bronzy-black. The fore-wings have @ paler patch near the apex, 
containing two small, and three large black ocelli with white 
centres; these ocelli are usually joined together. On the under 
side all the wings are considerably paler and greyer. The hind- 
wings have a series of pale spots near the termen, and a paler 
shade across the middle. 
This insect varies chiefly in the number of ocelli. On 
the upper side of the fore-wings there are sometimes only 
four, the minute ocellus on the costa being absent, whilst 
occasionally a small extra ocellus appears below the normal 
series. On the under side this last-mentioned ocellus is very 
frequently, but not invariably, present. In some female 
specimens an extremely minute ocellus may be detected on 
the upper surface of the hind-wings near the termen. On 
the under side of the hind-wings in both sexes the series of 
pale terminal spots is often absent, and the general depth 
of the colouring varies considerably. Generally speaking, 
specimens from the southern mountains are considerably 
larger and darker in colour than those from the Nelson Pro- 
vinee. <A very small and extremely dark form, with many 
eclden scales on the under side of the hind-wings, was, how- 
ever, discovered by Mr. Harold Hamilton, on the upper Ar- 
row River, and on Mount Hyde, at an elevation of about 
6,000 feet above the sea-level. This form was described by 
Mr. Augustus Hamilton as Hrebia pluto variety micans* 
In addition to these colour varieties, a most interesting 
structural variation often occurs in this species, vein 11 
of the fore-wings sometimes running into 12 and some- 
times being entirely absent. (Plate B., figs. 25, 26.) 
The perfect insect appears from December till March, 
and it is quite possible that there is more than one brood 
in a season. It frequents shingle slopes on mountains, at 
elevations ranging from 4,000 to 6,000 feet above the sea- 
level. Sometimes the butterflies occur in considerable num- 
bers, flying in a lazy, aimless manner in the scorching sun- 
shine, but instantly retreating into crevices between the 
stones when the sun is obscured. I have observed that this, 
species is most abundant in the neighbourhood of the ecar- 
pet grass (Poa colensoi), on which I fully anticipate its 
larva feeds. It seldom, however settles on this grass, pre- 

Ss RTANS Nese el Nst., oxlis 47. 
ferring to alight on the shingle, which, owing to the rare- 
fied air existing at such high elevations, soon becomes in- 
tensely heated by the sun’s rays. 
When disturbed this insect flies with considerable 
rapidity and thus often eludes the net, so that the capture 
of a good series of specimens on a rugged mountain-slope 
is usually very exciting, if not actually dangerous work. 
As with many other alpine insects, mountain ranges are 
more prolific in this butterfly than isolated peaks. This 
species has, on one or two occasions, occurred in river-beds 
amongst the mountains at elevations of about 2,500 feet. 
Its occurrence at such a low altitude must, however, be re- 
garded as very exceptional. 
EREBIA BUTLERI. 
(Erebiola butleri, Fereday, Trans. N.Z. Inst. xii. 264; Catalogue 
of N.Z. Butterflies, 19.) 
(Plate IV., fig. 3 4,4 9,5 @ underside.) 
This interesting butterfly was discovered by Mr. John 
D. Enys at Whitcombe’s Pass, Canterbury, on March 8, 
1879, at an elevation of about 4,000 feet’ above the sea- 
level. Since that time it has been taken in considerable 
numbers on the Humboldt Range, at the head of Lake 
Wakatipu, and on the high grassy country around Lake 
Harris, as well as on Mount Earnslaw and Mount Cook. 
It is, however, a very much rarer and more local species 
than Erebia pluto. — 
The expansion of the wings of the male is 1% inches, of the 
female 13 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 sur- 
rounding 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, dnd 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 moun- 
tain grasses, 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 H. pluto when on the wing. 
Immediately a cloud obscures the sun these butter- 
flies retreat into the grass tufts, remaining closely hidden 

