21 
The discarded skin of the caterpillar host is slightly or not at all 
attached to the cocoon or to the leaf or bark by the parasitic larva. It 
is usually blown away by the wind in a short time, but sometimes 
remains attached by its prolegs, or perhaps by silk which it spun before 
its death, to the leaf or bark upon which it happens to be at the time, 
so that the appearance shown in fig. 7 is frequently observed. 
Observations made in late August seem to indicate that the period 
from the completion of the cocoon to the issuing of the adult insect 
is only from seven to ten days. [Four specimens of the adult were 
reared altogether. These issued two on August 29, one on September 
17, and another on September 21. The remainder of the cocoons just 
referred to as having been more or less numerous gave out secondary 
parasites, the most abundant being Spilochalcis debilis, which will be 
treated more or less in detail in a later paragraph. 
The Amorphota in issuing from its cocoon gnaws anirregular round- 
ish hole at one extremity, of perhaps two-thirds the diameter of the 
cocoon itself, but if a cap is thus removed it does not remain attached 
by a hinge and has not been ob- 
served. The orifice in none of the 
cases noticed was made at the 
center of the tip, but a trifle to one 
side, as shown in fig. 7, presenting 
almost the appearance of having 
been pierced by a hyperparasite. 
Meteorus communis Cresson. 
This common and widespread 
species was a more or less important 
factor in the reduction of the num- 
bers of the tussock-moth caterpillars Fia. 8.—Meteorus communis: Adult female from 
iMmeaiherearlysauhumn Of 169b.cand ~ side; with empty. cocoon” showing cap—en: 
é larged (original.) 
would doubtless have been a still 
more important factor in the early summer of 1896 were it not for the fact 
that in the autumn of 1895 it was attacked by secondary parasites to 
such an extent that in 1896 not a single specimen was found or reared! 
This insect, which belongs to the family Braconidie (whereas the others 
previously considered belong to the Ichneumonidie), is recorded by 
Cresson from Canada, Connecticut, and New Jersey, and occurs in 
the National Museum from Texas, Missouri, and the District of Colum- 
bia. It has been reared from Tineids, Botids, and Bombycids, and 
with Orgyia leucostigma attacks the half-grown larvee in much the same 
manner as does the Amorphota previously described. The parasitic 
larva issuing from the body of the half-grown caterpillar, which imme- 
diately becomes shriveled and distorted, spins for itself an oval cocoon 
of tough, parchment-like brown silk, over the surface of which are seat- 
tered threads of a coarser and lighter-colored silk. The toughness and 
