232 THE ENTOMOLOGIST. 
question can be certainly distinguished, but I should like to draw 
attention to some points of difference which may assist collectors 
in naming the “‘ daggers ” correctly, and at the same time to draw 
forth similar remarks from other observers. 
I have in my cabinet a series of ten Acronycta tridens and 
twelve A. psi, every one of which has been bred by myself from ~ 
the larva, and most carefully kept separate and labelled. I can 
therefore say positively that the insects are rightly named, as 
thereis no difficulty in distinguishing the larva. 
1. What strikes me on the first glance at the two series, side 
by side, is that Acronycta tridens, as compared with A. psi, is the 
smaller and darker of the two. Newman, I am aware, says 
that A. tridens is no darker than A. psi; but with due respect 
to his authority I maintain that the difference of shade is 
distinct. 
2. Looking more closely at the insects I find that there is also 
a difference in the general colour of the fore wing. In A. psi it 
is pure grey, varying in shade, of course, in different specimens, 
some being dark grey, others paler; but the grey is pure in all, 
that is, a mixture of black and white only ; whereas in A. tridens 
a third colour, ochreous-brown, is added, so that the general 
colour is warmer, and of a brown-grey hue. In A. psi there 
are parts of the fore wing (as the inner part of the subterminal 
line) which are often pure white. In A. tridens even the whitest 
parts are suffused with ochreous, and there is no part pure white. 
8. With regard to the markings. All the markings of the 
fore wing in A. psi are more abrupt and defined than in A. tridens, 
whereas in A. tridens the markings are blended with the ground 
colour by the soft brown tint which suffuses the whole wing. 
4. There are one or two marks which call for attention in 
particular. With reference to the t-like mark at the anal angle, 
this mark is somewhat different in the two species. In both it 
consists of a longitudinal black dash crossing a diagonal curved 
black line. Now in A. psi the curved line is darker and heavier 
than in A. tridens. Moreover, the longitudinal dash is shorter in 
A. tridens than in A. psi. In A. psi this straight black dash 
extends from the fringe through the subterminal line and beyond 
towards the base; but in A. tridens it scarcely” passes the 
subterminal line. 
5. The scales on the head and palpi in Acronycta tridens are 
