OXIGRAPHA LITERANA, L. 131 
was at least three weeks in advance of the average. On the 11th 
of the month the oaks were breaking into leaf. The few ova I 
obtained in 1917 were not deposited until April 27th—a date 
I should consider about normal in an average season. 
Tore Larva. 
The first larva appeared on April 26th; this was from one of 
the earlier deposited ova, and therefore it would appear that this 
stage has a period of about three weeks. 
A larva which emerged on May 2nd was kept under observa- 
tion in all its stages, and the following notes were taken of it : 
The length at first is about 14 mm. The head is intensely 
black and very glabrous ; the rear portion consists of two promi- 
_ nent lobes, which have rounded bases. ‘The head itself is some- 
what acutely pointed in front ; it is furnished on each side of the 
mouth with a prominent excrescence, which, owing to the small- 
ness and activity of the larva, it is difficult to determine the 
structure of, but they appear to be tubercles emitting spines, 
and they are certainly retractile.* The prothorax is greenish ~ 
white and very glabrous. The segments at the rear of the pro- 
thorax are greenish white and very spiny ; the prolegs are large ; 
they are greenish white in colour. The head is very large in 
proportion to the size of the body. 
This larva was put in a small tin box with two oak leaves, 
one placed over the other ; it mined in the first instar between 
the upper and lower cuticles of the upper leaf, entering from the 
lower side. 
On May 14th the larva was in the second instar; it was now 
about 2mm. long. The head and prothorax are intensely black 
and glabrous ; the division between the two is wide and greenish- 
white in colour; the segments behind the prothorax are greenish- 
white and very transparent, the alimentary canal showing very 
distinctly. The prolegs are greenish-white, tipped and shaded 
with black ; the larva is very spiny, the spiracles are not con- 
spicuous. ‘The retractile organs on each side of the mouth are 
not so prominent as in the last instar, but they are still dis- 
tinctly visible. The larva in this instar does not mine the leaf, 
but feeds upon the lower cuticle, spinning a web alongside the 
midrib and dwelling therein. 
On May 28rd the larva was in the third instar. It was now 
5°75 mm. long, light greyish-green in colour, very transparent, 
with the contents of the alimentary canal very distinct; head 
and prothorax intensely black and glabrous, the division be- 
tween the two similar to the preceding instar. There is no trace 
of an anal plate. The larva is very spiny; the prolegs and feet 
* Since writing the above I am informed by Dr. Chapman that these pfotube- 
rances are probably the antenne. This question requires further elucidation when 
the material is available. 
