43 
species, and yet it is at present so imperfectly known that I feel I must 
not pass by this part of my subject. Westwood’s figure in his supple¬ 
ment to Wood’s Fnde.v Entomuloyicim, and still more Mr. Clark’s plate 
(pi. iii.), in Ent. Iiec., vol. vii.,* will, however, give a better idea of 
the insect than any lengthy description ; Newman’s second figure 
(Brit. Moth. s’, p. 108) also well represents the pale typical form, though 
the basal and the elbowed line are normally somewhat more strongly 
angulated. Beyond these indications, the type description which I 
have quoted from Borkhausen (Ent. lice., x., p. 93), and the notes 
which I gave in my earlier paper (Ent. lire., ix., pp. 315-316), there is 
perhaps little to add; hut the collective result of these notes and 
quotations, digested by myself and amended or amplified by my own 
personal observations, would be somewhat as follows : 
Size.— $ 32mm.-42mm.; 5 29mm.-39mm. (the smaller ones 
mostly bred specimens, hence, perhaps dwarfed); therefore larger than 
Jiliyranmaria, quite equal in size with dilutata : like the latter, it 
varies much in expanse, but on the whole, the $ s are less markedly 
smaller than the $ s, than is the case with diliitata. 
Shape. —Very variable, but the wings generally broader than in 
filiy ram maria, outer margin of forewings slightly more concave on its 
lower half than in dilutata, apex consequently appearing somewhat 
more produced. Similar features generally observable on hindwings. 
Perhaps also the costa of the forewings is a trifle straighter on the 
average than in dilutata, but this is far too inconstant to he of any 
real value. 
Antenn.e.—F iner in the $ than those of dilutata, the members 
being less swollen anteriorly. 
Colour. —Varies from white to almost black, yet always of a diffe¬ 
rent tone from the equally variable dilutata. Indeed the practised eye 
will differentiate the two species more readily by colour than in any 
other way. In autumnata the tone ranges from clear silvery to bluish 
or violet tinged, and even the blackest varieties show a strong gloss of 
purple-brown ; in dilutata, on the other hand, the white or grey is of a 
dirtier tone, and its tendency is to yellowish or greenish, while the 
dark forms run towards dull smoke-colour and black. Moreover, 
autumnata is a more glossy species than dilutata, being very nearly 
(but perhaps not quite absolutely) as glossy as jiliyranmaria, with 
which latter the ground tone also is practically identical. 
Markings. —These need not he described in detail, as they are 
shared by the whole genus Epirrita (Oporahia). The most character¬ 
istic points are : 
1. The angulation of the (generally strongly black) line bounding 
the basal area. This is often gently rounded in dilutata. 
2. The angulation of the “ elbowed line ” near the costa. This is 
variable in exact degree, frequently almost amounting to a right angle; 
but on the whole, it is the most convenient marking for purposes of 
differentiation from dilutata, which very rarely has it angulated. 
3. The general directness and freedom from zigzags in the course 
of the elbowed line from the angle down to the inner margin. 
4. The strongly pronounced black marks (in most specimens) at 
the bifurcation of the strong central nervure (cubitus), and to some 
See also Mr. Christy’s series figured in Entom., xxxiii.. pi. i. 
