Packard.] 
96 
[May 7, 
are somewhat everted so that the gland is slightly button-like. 
I could not detect any such opening in the same position behind 
the legs on the protlioracic segment, but in front of the legs in 
both specimens there seemed to be a transverse slit like that of 
Cerura, the slit having rather full lips. (It is possible that I have 
made a mistake in regard to the protlioracic opening, and that 
it may have been an accidental rupture, and my observations need 
confirmation by the examination of living specimens, and of a 
larger number of well preserved alcoholic ones, as everything de- 
pends on the mode and state of preservation of the caterpillars.) 
Then examining an alcoholic larva of the European Nola cuculla - 
tella (Linn.) kindly sent me by Dr. Heylaerts of Breda, Nether- 
lands, one was detected on the second and on the third thoracic 
segment, similar in appearance and position to those in N. ovilla , 
while a third one was seen on the protlioracic segment just behind, 
but nearly between, the origin of the legs ; the edges of the open- 
ing form a narrow, acute triangle ; and I could see no trace of 
such an opening in front. 
Since the foregoing paragraph was written I have received the 
following information regarding these organs in the European spe- 
cies of Nola kindly communicated by my friend M. P. Chretien 
of Paris, who writes me as follows: “I have examined the five 
species of Nola that I have in my collection of blown caterpillars ; 
all have what you call button-like glands between the thoracic feet 
of the second and third segments. N. strigula is the only one which 
has tubiform appendages near the thoracic feet ; but on the back 
of the fourth segment of N. cucullatella I have observed the pres- 
ence of two small tubercles.” It is not improbable that these sternal 
glands are homologues of the coxal glands of other Arthropods ; and 
the same ma}^ be said of the lateral and dorsal ones, their position 
being the result of adaptation. Since this paper was sent to the 
printer I have observed the protlioracic glands in action in the liv- 
ing larva of (Eclemasia concinna , and have observed it in alcoholic 
larvae of Pheosia rimosa , and in living larvae of Limenitis disippe 
(Astyanax archippus) . 
V. HINTS ON THE ORIGIN OF THE PROTHORACIC OR CERVICAL 
SHIELD. 
Not only in the wood-boring Lepidoptera, such as the larvae of 
the Hepialidae, and the Cossidae, as well as the Sesiadae, is there a 
well-marked cervical shield, but also in the grubs of Cerambycidae, 
