PST-CHE. 
‘be cut or pushed aside to allow the es- 
cape of the imago within. I have never 
studied this gland and will refer for fur- 
ther notice to the easily accessible papers 
of Trouvelot,’ Packard,? McLaren? and 
Worthington,” wherein references 
be found to earlier European writers on 
this subject. 
It is an easy transition from the glands 
of the larvae of Aftacus, Hyperchiria 
and Hemileuca, closed by brittle, hollow 
spines or hairs, to the glandular hairs 
of certain larvae of pterophoridae, where 
the hairs are apparently burst open at 
their tips by the pressure of the secretion 
within them, the liquid then oozing out 
to form a dew-like drop upon each hair. 
Zeller” mentions glandular hairs (‘‘drti- 
senhiirchen”) on the larvae of Mimeseo- 
ptilus phaeodactylus and M. mictodactylus, 
but says nothing of the structure or use 
of these hairs. Miss Murtfeldt’® writes 
of the larva of Leioptilus sericidactylus 
‘*Dorsal hairs proceeding from prominent 
tubercles, and of two sizes in each tuft, 
each of the shorter ones tipped with a 
minute pellucid bead of viscid fluid, to 
which pollen and bits of leaves often ad- 
here.” I have found the larva of Acipti- 
lus lobidactylus to be covered, in like 
manner, with glandular hairs. 
Upon making transverse sections of 
the larva of Aciptilus lobidactylus, its ex- 
ternal surface is found to bear three 
kinds of appendages. First are the very 
minute, but obtuse spines (about 0.01 
mm. long) which clothe most softer and 
more flexible portions of its external 
covering, and which are found on many 
larvae of different orders of insects. 
7a 
389 
Second are hairs (from 0.08 to 0.14 mm. 
long) more or less dumb-bell or club 
formed, which are filled with granular 
matter, and seem to be set usually only 
upon the surface of the chitinous cover- 
ing of the larva. Third are the longer 
hairs (from 0.8 to 1.38 mm. long), linear 
or slightly clavate, usually burst at the 
tip, or sometimes along the sides, and 
where burst surrounded by a drop of 
exuded gummy matter. These last hairs 
are mounted, by a kind of joint such as 
is often present at the base of insect 
hairs, upon or near the summit of little 
conical elevations, which rise about 0.2 
mm. above the surface of the dorsal and 
lateral parts of the larvae. These 
hairs are arranged systematically and 
symmetrically upon the different seg- 
ments of the larva, the most prominent 
of them being a pair upon a conical 
elevation just at each side of the median 
dorsal line of each segment. A com- 
parison of the arrangement of these hairs 
and prominences with the arrangement 
of hairs and warts upon other lepido- 
pterous larvae, especially of those upon 
the larvae of tortricidae, would be an 
interesting study. The interior of hairs 
of this third form opens at the base into 
the conical prominence or wart on which 
the hair is situated. The prominence is 
probably entirely; filled by the gland 
which secretes the viscid matter that 
finds outlet through the hair. 
The specimens of the larva of which 
I made microtomic sections were not 
quite well enough preserved to admit of 
carefully studying the gland at the base 
of the hairs. The hairs of the second 
