iE euy ©deb bs. 
THE TROPHI AND THEIR CHITINOUS SUPPORTS IN GRACILARIA. 
BY GEORGE DIMMOCK, CAMBRIDGE, MASS. 
The papers upon Lithocolletis by Mr. V. 
T. Chambers, which have appeared from 
time to time in Psycue,' supplemented by 
the notes and figures on the same subject 
contained in his address as retiring presi- 
dent of the Cincinnati Society of Natural 
History,” inspired me with the desire to 
study further the mouth-parts of the larvae 
of Tineina, especially in their earlier 
stages. The abundance of Gracilaria 
syringelia in the leaves of the lilac (Sy- 
ringa vulgaris), about Leipzig this sum- 
mer, gave me plenty of material, and the 
opportunity of studying the larvae under 
the direction of Professor Leuckart was not 
lost. 
Altho the larvae were so numerous in 
some of the gardens about Leipzig that 
searcely a leaf of the lilac escaped their 
depredations, I attempted to learn but little 
of their mode of life. During their early 
stages, when they have the flattened larval 
form, they mine in the upper side of the 
leaf. They then have the form of head 
and mouth-parts represented in fig. 2, and 
their legs are mere rudiments. A little 
1Psycue, Nov.—Dec. 1877 | April 1878], v. 2, p. 
81-87; May—Aug. [Nov.] 1878, v. 2, p. 187-153; 
April 1879, v. 2, p. 227. 
later they assume the form of head and 
mouth-parts shown in fig. 3, and begin to 
eat away all the parenchyma of the leaf, 
leaving only the upper and lower epider- 
mis; still later they leave the mines and 
roll the ends of the leaves, feeding within 
the rolls. Upon changing the form of 
mouth-parts from that represented in figure 
2 to that represented in fig. 4, true legs are 
developed, the secretion of silk is begun, 
and the larvae become more cylindrical. 
A striking resemblance to the changes 
which Mr. Chambers has observed in the 
cylindrical larvae of Lithocolletis is ob- 
served in the above-mentioned changes of 
the larvae of Gracilaria. 
as ten or fifteen larvae are found in a single 
blotch on the leaf. I succeeded in rearing 
the larvae easily by simply transferring 
Often as many 
leaves containing them to a box, in which 
I packed many leaves closely together. 
The leaves, thus packed, retained moisture 
and the larvae deserted the mines to wan- 
der about between the leaves, where they 
fed until ready for pupation. I am in- 
debted to Professor Zeller, for the determ- 
2 Journ. Cincinnati Soc. Nat. Hist., July 1879, 
also Separate, 22 p. [Psycue, Rec., no. 1805.] 
