all 
298 Mr. J. W. Douglas’s Observations on the 
an ecdysis, and be developed into the large adults found 
at the end of May on Stellaria holostea, when the large 
egg-pouch or marsupium, which has been originated in 
the meantime, is full of yellowish eggs (about thirty) 
enveloped in a fine cottony web or flue. 
On the adult female, whose total length is 23 lines, 
there is first, a large, thick, bilobed projection over the 
head ; conjoined to this, on the dorsal surface of the 
body, are two highly projecting parallel ridges, composed 
of seven or eight thick, subangular, backwardly directed, 
closely overlapping plates, leaving between the ridges 
a deep longitudinal furrow, which, like them, extends to 
the end of the body. The furrow is quite regular and 
smooth, but at the base of the ridges on the outer side is 
generally a series of small supplementary scales; by 
these ridges the segments of the body are quite hidden. 
The circumferential lamine, starting at right angles to 
the base of the frontal projection, somewhat narrow and 
rounded on their anterior margin, directed backwards, 
project laterally, in regular succession, to a considerable 
extent, each lamina (on the sides) (6 to 7) showing 
a little beyond the one immediately preceding it, the 
posterior ones (three on each side) being greatly 
elongated, sometimes curved, and lying in the side 
grooves of the marsupium, but not above half their 
length, and the terminal middle one, arising just at the 
anal orifice, either lying depressed in the middle groove 
of the marsupium, or elevated at an acute angle. I am 
not sure if this elevation be a voluntary act on the part 
of the insect, nor if the lamina ever assume the pro- 
cumbent position; often it is broken off, for all the 
lamine are removable with the slightest touch. 
The marsupium, consisting of cereous matter of a 
thin shell-like structure, formed (apparently) in two 
plates, at any rate easily separable into two, is attached 
at the base to the abdomen, but extends far beyond 
it; the lower plate convex ; the upper one flattened, the 
space between them forming a large cavity in which the 
egos are deposited and hatched. ‘The lower plate arises 
immediately behind the posterior coxe, and is perfectly 
smooth ; the upper plate, constituting half the apparent 
length of the insect, has its surface deeply channelled 
lengthwise, the middle channel wide and rounded out, 
the others (three on each side of it) narrow, the inter- 
vening divisions thin, simulating lamine, as I previously 
termed them. 
