THE GENUS ACRONYCTA AND ITS ALLIES. 
175 
which two emerged quite satisfactorily, ordinary full-sized 
specimens, and the third is alive and well, and proposes to 
face a fifth winter as a pupa. 
^In this district it affects aspen as its proper food, but occurs 
on other species of poplar. I have seen it, but very rarely on 
sallow ; it does not range far north, at least on the west coast, 
but I do not know its exact limits. 
Notes on Plate III. — The pupae here illustrated are the 
most typical CuspidicB. They all have the two dorsal hooks, 
and of the three ventral hooks on either side, all have the 
two inner ; alni, sirigosa and tridens have also the outer in typical 
form ; psi has this outer one simply, or more usually duplicated 
into two on either side. In megacephala it is represented by a 
lateral group or 6 or 7 hooks. Taking tridens for comparison, 
then psi is extremely similar, strigosa, though of the same 
pattern, has the hooks very long and delicate, proportionally 
(to the smaller pupa) about twice as long. Altii has the hooks 
much the same, but more spread and more hooked, and has in 
addition the remarkable special groove, with its fluted margin 
and remarkable smooth escutcheon on the boss below. In 
Glea there is a suggestion that such a structure might arise, 
but I am not acquainted with any other pupa with this groove 
fully developed. The drawings, which are well reproduced in 
the plate, convey a very accurate impression of these struc- 
tures, and are indeed most excellent and successful. Only in 
megacephala is the success at all modified. 
EXPLANATION OF PLATE III. 
Fig. 
Natural Size.— I. — Pupa of Aoonycta {Cuspidm) psi. 
Enlarged J 
la. „ 
8 diameters. | 
. Ib- 
>) 
Natural Size.- 
-2. 
f 2 a. „ 
Enlarged , k 
8 diameters. ” 
5) 
5) 
l2d. 
)) 
Natural Size.- 
-3* )» 
>) 
Enlarged 1 
9 diameters. ^ 
fSa. 
3b. „ 
l3c. 
-4. 
>9 
Natural ”^ize.- 
)> 
)9 
Enlarged 
9 diameters. ' 
.. 
Uc- » 
)> 
Natural Size.- 
-5- 
n 
Enlarged 
; 5b. 
J3 
6 diameters. 
1 5C. 
>5 
,, dorsal view of anal armature. 
„ ventral „ „ 
tridens. 
„ dorsal „ 
„ ventral „ 
„ terminal „ 
strigosa. 
,, dorsal ,, ,, 
„ ventral „ 
„ lateral „ 
alni. 
„ dorsal ,, ,, 
„ ventral „ 
„ lateral „ „ 
megacephala. 
,, ventral „ ,, 
„ lateral ,, 
{To be continued.) 
