THE GAMMA-MOTH. 
239 
towards the tip ; proboscis long ; head and thorax 
both crested ; the abdomen, which is rather long 
and thick, likewise bearing tufts at the base and 
along the back ; fringe of the anterior wings slightly 
emarginate, that of the posterior entire : caterpillars 
half loopers, poasessing only four rentral legs and 
the usual posterior pair. Such are the distinguish- 
ing characters of this handsome genus, which con- 
tains about a dozen indigenous species. All of 
them are remarkable for the rich metallic marks 
on the anterior wings, which sometimes assume 
the appearance of rvritten characters. They fly 
during the day, skipping about from one plant 
to another in a restless manner, and rvith much 
rapidity, keeping their wings, while feeding, in con- 
stant Vibration, somewhat like the Humming-bird 
Hawk-moth. The most common and best knowm 
of these insects is represented on the adjoining plate. 
It measures from an inch and one-third, to upwards 
of an inch and a half; the upper wings grey, varie- 
gated with dusky brorvn, having a pale blotch ante- 
riorly towards the apex, and a few transverse slightly 
waved dark lines ; the disk of each inscribed with a 
silvery character, resembling the letter Y, or rather 
the Greek 7 ; fringe somewhat dentate, greyish, 
spotted with dusky brown. Hinder "wings ash- 
brown, the nervures and hinder margin deep bro"\vn; 
the fringe light-coloured with dark spots. The head 
and thorax are ash-grey ; the abdomen rather of a 
lighter hue. 
The colour varies considerably in intensity, and 
