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habit of the females of this genus never to quit the case, or rather, never to leave the 
pupa-skin, but to turn the body round within the pupa-skin so as to bring the sexual 
part in contact with that of the male; in the present case it would appear that copula- 
tion had not actually taken place, but the males were destroyed in that position by 
reason of their extended peves having been caught in the silken or woolly matter 
which formed the interior lining of the case, and their escape thus prevented. 
Mr. Dunning mentioned that, in the year 1850, when strolling in the vicinity of 
Storthes Hall, Huddersfieid, in company with Mr. Inchbald, they had found two 
males of Micropteryx calthella simultaneously in sexual contact with a single female: 
unfortunately neither genticman had any entomological apparatus with him, and the 
specimens could not be secured; they were, however, carried for upwards of a mile on 
the dandelion-flower on which they were reposing, but after this interval the contact 
was discontinued, and the moths flew away. (See Zool. pp. 2501, 2830, 2858, as to 
this species frequenting the dandelion and other flowers.) 
Mr. Bates read a letter from Mr. B. D. Walsh, of Rock Island, [linois, dated 
April 22, 1865, from which the following are extracts: — 
“‘T have read your paper on mimetic Lepidoptera with the greatest interest. I am 
naturally of a sceptical turn of mind, and apt to require rigid proof uf everything ; 
but although I had rather a prepossession against the truth of your theory befure 
I commenced reading, I am now quite convinced that you are perfectly correct. 
Judging from your figure of Leptalis Nehemia, the resemblance in shape of wings— 
which I find to be a pretty constant character in Lepidoptera—is, if possible, still 
more remarkable than the resemblance in coloration between Leptalis and Ithomia. 
“ We have in this country a somewhat similar mimetic analogy between Danais 
plenippus and Limenitis disippus, insomuch that a certain Professor in a popular book 
on insects figures the latter under the name of the former! They do not fly in com- 
pany, but as the former is strong on the wing, and the latter rather sluggish for a 
butterfly, may it not be the case that by the resemblance birds have been deceived into 
the belief that it is no use to pursue it? Plenippus is very common here, Disippus 
rather rare. 
“I have discovered within the last few days that the larva of this Disippus is 
remarkable for hybervating in the immature larva state in a case made of a willow-leaf, 
which it first secures by silken cabies to the twig. The case is made by cutting away 
most of the terminal portion of the leaf, and then joining the remaining edges together, 
so that the whole somewhat resembles the leaves of some pitcher-plants (Sarracenia). 
As a rule, with the exception of Hesperide, which osculate with Heterocera, the 
Rhopalocera do not roll up leaves to live in, though Cynthia Cardui makes a rude 
kind of tent for itself, while the closely-allied Cynthia Huntera, unless my memory 
deceives me, makes no tent at all. Mr. Lintner, in his paper, Proc. Ent. Soc. Philad. 
iii. 63, says that he captured Disippus ‘early in May, appearing as if it had survived 
the winter.’ It must have been larve that had ‘fed up’ in the spring that produced 
his imagos. The second brood comes out late in the summer, after remaining only a 
week or so in pupa, from larve which, so far as I have hitherto observed, do not con- 
struct any cases to live in, seeing that they have no hybernation to go through in that 
state. Thus it seems we have a kind of metagenetic habit of leaf-rolling, which 
appears only in alternate generations. I found altogether 12—20 of these larva-cases 
on Salix humilis, several containing litle larve, a quarter to half an inch long, 
