66 
obeliscata seem to beon an average, somewhat darker than the continental, 
the majority of which are of the quite bright fulvous forms. 
T. obeliscata, though so much the more abundant with us, has 
apparently a much more restricted geographical range than variata. 
Staudinger only gives Central and Northern Europe, Castile and 
Armenia, and I cannot add to this; variata, on the contrary, reaches 
right across Asia to Japan, though it does not, like its relative, extend 
into Arctic Norway. In North-West Africa occurs a smaller, closely 
related species, variolata, Stgr. In Japan, besides true variata, there 
is a variata-\\\iQ species (conns, Butl.) with pectinate $ antennas, and 
the projection of the median band more rounded and placed more 
posteriorly. In North-West India and Afghanistan another similar 
pectinate Thera (consimilis, Warr.), with the veins blackened, especially 
near the apex, rather recalling cupressata, Hb.-G. I know of no other 
very close allies. 
Regarding the habits of the newly-discovered British species, 
T. variata, I can say nothing at first hand, but I believe them to be 
nearly the same as those of our obeliscata. I need hardly remind our 
lepidopterists that this well-known species rests on the trunks or among 
the branches of the Scotch firs, and when beaten out is fond of dropping 
or fluttering pretty straight to the ground where it finds an easy 
hiding-place among the fallen needles. It is without doubt protec¬ 
tively coloured and I have seldom noticed it at rest unless it happens 
accidentally to have chosen some unsuitable resting place, such as a 
black fence. Like several of the Geometers, it is addicted to sitting 
with its wings closed over its back after the manner of a butterfly ; 
and this is not only when it is on its nocturnal peregrinations—in which 
event this is the invariable attitude of rest—but also very generally 
when it has been beaten out by day, and even for quite a long while 
after it has been enclosed in the entomologist’s box. This is rather 
provoking, as the underside does not vary at all appreciably and, this 
alone being then exposed, the collector is unable to see what forms he 
is taking. The variability being exclusively on the upperside is 
sufficient proof that the true resting posture is with the wings spread 
flat. There are exceedingly few British Geometrids (chiefly “Thorns ) 
which show evidence of specially adaptive under surfaces. 
The larvas of both variata and obeliscata hibernate, or probably go 
on nibbling during the mild spells of weather of which an ordinary 
English winter provides plenty. The moths appear in May or June. 
From some dates which I have culled from Continental magazines, it 
would appear that variata in some localities begins a little earlier 
about the middle of May, obeliscata towards the end of the month. 
The last-named is pretty regularly double-brooded, turning up again 
in August and September. The double-broodedness of variata is 
possibly more partial, though I cannot assert this with any confidence. 
That T. variata has comparatively recently been introduced into 
Britain with some ornamental pines, seems to me on the whole more 
probable than that it has been entirely overlooked. As I have 
remarked in “ The Entomologist” it is worthy of note that our ordinary 
British Thera (obeliscata), is the one which is attached to our only 
iniligenons British pine, but both species are pretty adaptable as to their 
xxii. \xiii. 
