Art. XXVII.—Description of a new (?) Genus and Species of Butterfly of the Sub-family Satyrinæ.
[Read before the Philosophical Institute of Canterbury, 5th June, 1879.]
Erebiola, nov. gen.
Antennæ, the club much narrower and longer than in Percnodaimon pluto, but not so narrow or long as in Erebia blandina. Eyes, naked. Labial palpi rather longer, and densely clothed with much longer stiffish hairs than in P. pluto; the hairs of the tip forming an obtuse-pointed pencil. Body and legs clothed with rather longer hairs than in P. pluto.
Wings entire. Primaries rather more elongate, and hind margin more oblique than in P. pluto; the nervures and discoidal cells of both the primaries and secondaries very similar to those of P. pluto; except that in P. pluto, the first (c, fig. 3) sub-costal nervure is absent, and the space
between the externo-medial (a, figs. 2 and 3) and innermost (b, figs. 2 and 3) sub-costal nervures,* at their junction with the vein closing the discoidal cell, is rather broader than in P. pluto; none of the nervures dilated at the base.
The accompanying diagrams (plate IX.) represent:
Fig. 1. The disposition of the nervures in the primary wings of E. blandina.
2. Do. do. do. do. P. pluto.
3. Do. do. do. and secondary wings of E. butleri.
and are given for comparison; the figures enlarged to two diameters.
Not having the descriptions of all the genera of the Satyrinæ, I should hesitate in forming a new genus for this insect; but, as “the lower radial of primaries emitted above the angle of the discocellulars instead of below it,” is given by Mr. Butler† as one of the distinctive characters of his new genus Percnodaimon; and as the now-describing butterfly has the like character, but disagrees with Percnodaimon in the form of the club of the antennæ, and the presence of the first sub-costal nervure;‡ I may reasonably assume that it differs from all the other genera, and have therefore ventured to describe it as a new genus.
Erebiola butleri, sp. nov.
Primaries: Upper-side smoky black; a white-pupilled black ocellus between the externo-medial and innermost sub-costal nervures, and equidistant between the discoidal cell and hind margin. Under-side ferruginous, suffused (except the apical and hind-marginal area) with slaty black; ocellus as on upper side; a sub-hind-marginal row of four whitish marks, the two nearest the apex being the more distinct and silvery, followed by a dusky shade on their outer margin.
Secondaries: Upper-side smoky black; a transverse row of three minute white dots near the hind margin; the dots arranged in a straight line pointing towards the anal angle, and situated respectively between the externo-medial, subexterno-medial, interno-medial, and subinterno-medial nervures. Under-side ferruginous, suffused with a dusky shade from the base to the transverse row of spots; a longitudinal discoidal streak of silver; a transverse row of three silvery spots near the hind-margin, followed by two small longitudinal silvery streaks near the anal angle; also,
[Footnote] * The Orismology in Kirby and Spence's Introduction to Entomology (the only authority I have) is followed in describing the nervures.—R.W.F.
[Footnote] † Ent. Mo. Mag. XIII., p. 152.
[Footnote] ‡ As Mr. Butler does not mention the absence of this nervure in describing his genus Percnodaimon, I imagine he must have overlooked it.—R.W.F.
a small longitudinal streak of silver between the latter streaks and the base of the wing; the transverse row of spots consists of a conical spot—between the externo-medial and subexterno-medial nervures, with its apex pointing to the hind-margin; a sagittate spot between the subexterno-medial and interno-medial nervures; and a similar one between the externo-medial and subexterno-medial nervures, all bordered internally with a dusky shade; the latter two spots pointing towards the base of the wing, and each followed towards the hind-margin by a small silvery dot, between which and the hind-margin is a small silvery point, edged externally with black; a small pale, irregular subcostal mark near the base of the wing; and on the costa, two-thirds from the base of the wing, a larger pale triangular mark, followed by two pale irregular spots.
Male and female alike, except in size.
Expanse of Wings: male, 18 1/2 lines; female, 20 lines.
Habitat: Whitcombe's Pass, Canterbury, New Zealand.
I have described this butterfly from three dilapidated specimens brought to me by J. D. Enys, Esq., who has favoured me with the following account of their capture:—“I caught the three butterflies on Whitcombe's Pass, up the Rakaia, on the 8th of March, 1879. The Pass is over 4000 feet, and the first of the butterflies was caught close to the top; the others were near it. They were knocked down by my hat and put in paper, which must be my excuse for their state. They seemed to be rather slow in their flight, and were chiefly found on the snow-grass (of the family Danthonia) which covers the slopes of the hills at that height. I saw a number, but only got four.”
In the accompanying coloured drawing (Plate IX.), figure 4 represents the male; a, the under-side; b, the upper-side.
I have named the butterfly after Mr. A. G. Butler, who has recently contributed valuable lists of, and papers on, the Lepidoptera of New Zealand, and to whom I am much indebted.
[Since writing the above, Dr. Julius Von Haast informs me that it was a specimen of this butterfly which he took in 1866 on Whitcombe's Pass, not of P. pluto, as he before stated (vide “Trans. N.Z. Inst.,” Vol. IV., p. 217). Dr. Von Haast speaks from recollection, not having preserved the specimen he took.]