BSP. 
become greenish or whitish and opaque 
after some time; and, if exposed to too 
dry an atmosphere, both pupation and 
the exclusion of the imago are rendered 
impossible or difficult. Therefore, I 
imagine a close, membranaceous cocoon 
is a necessity.” : 
I have found, in examining a large 
number of specimens of cocoons of C. 
scrophulariae, no exception to the exis- 
tence of punctures in them, altho the 
punctures are never large enough to be 
termed open meshes. Were it not for 
these punctures the cocoons of C. 
scrophulariae would be, to all appear- 
ances, hermetically sealed. ‘This is not 
the case with the cocoons of bombycidae, 
as can be seen readily, by covering a 
portion of a cocoon with soapy water 
NOTES 
415 
and blowing through the portion to be 
tested. The numerous bubbles 
form on the outside in such an experi- 
ment are clear proof of the passage of 
air through the cocoon-walls. Even the 
very compact inner lining of the cocoon 
which 
of Altacus promethea readily allows the 
passage of air. 
Treated with dilute acids the cocoon 
of C. scrophulariae shows little change ; 
alkalies dissolve out of it, as they do 
out of cocoons of bombycidae and even 
out of portions of insects themselves, a 
brownish-yellow coloring matter, which 
loses its color on being acidulated, and 
regains it upon again making the solu- 
tion alkaline. The whole cocoon of C. 
scrophulariae is soluble in strong nitric 
acid. 
ON PTEROPHORIDAE OF NORTH AMERICA, 2. 
BY GEORGE DIMMOCK, CAMBRIDGE, MASS. 
In the list of references concerning 
pterophoridaz which I published in 
PsycuE, Sept.-Oct. 1883, v. 3, p. 402- 
404, I omitted, by some accident, all 
references to a paper published by Dr. 
D. S. Kellicott in the Bulletin of the 
Buffalo society of natural sciences for 
January 1882, and afterwards as a 
separate. Wishing to make my notes 
as complete as possible I add the follow- 
ing data taken from that paper, the title 
of which is ‘‘ Notes on the larvae of some 
local pterophoridae.” 
Platyptilus carduidactylus Riley. Kelli- 
cott (Bull. Buffalo soc. nat. sci., Jan. 1882, v. 
4, P- 47) gives notes on the larva and pupa 
of this species, and states that it is often 
parasited by a variety of /chneumon humilts, 
Provancher. 
Oedematophorus cretidactylus Fitch (1st 
and 2nd Repts. nox. ins. N. Y., 1856, p. 142). 
Kellicott (Bull. Buffalo soc. nat. sci., Jan. 
1882, v. 4, p. 48-50) describes the larva and 
pupa of this species. The gregarious larvae 
feed upon Eupatorium purpureum, the 
leaves of which they fasten together with a 
web. N. Y., Cal., Vancouver’s Isl. 
Lioptilus homodactylus Walk. Kellicott 
(Bull. Buffalo soc. nat. sci., Jan. 1882, v. 4, p. 
48-50) describes larva and pupa of this spe- 
cies. The gregarious larvae feed among 
leaves of Eupatorium purpureum which they 
have webbed together. Buffalo, N. Y. 
Actptilus montanus, Wlsm. Kellicott 
(Bull. Buffalo soc. nat. sci., Jan. 1882, v. 4, 
p- 51-52) describes larva and pupa; the former 
feeds upon the leaves of different species of 
Solidago. Buffalo, N. Y. 
