164 
IOWA ACADEMY OF SCIENCES. 
the fourth, but in some cases the fifth and sixth are also light 
colored except the distal part. The dark colors of the thorax 
and legs are also liable to vary, On the abdomen, in some 
cases, the black markings could be traced slightly below the 
pleurum, being most noticeable in the males, which are usually 
a little smaller and darker than the females. 
The intensity of these markings may be due largely to the 
length of time from their issuing as adult and their being 
killed. The older the more intense are their color markings. 
Still this cannot be taken as an invariable rule. Some speci- 
mens seem to have their colors more intense than others, 
although they are of the same age. This same fact of color 
variation is also noticed in the larvae. Some are more intense 
than others, and the marks somewhat differently arranged. 
The life history has not been traced carefully enough, as yet, 
to say whether the darkest larvae produce the darkest adults, or 
whether this larval variation has any effect on the markings of 
the adult. 
The first specimens were taken by Mr. E. D. Ball in August, 
1894. The adults and the larvae could be collected from that 
time on till the leaves fell in November.. They are quite incon- 
spicuous, because their coloration blends very nicely with that 
of the leaves and twigs, thus bringing out very nicely the sub- 
ject of protective resemblance. This is very noticeable through- 
out the family. 
Larva . — The young larvae are thin, flat, scale-like, very 
closely applied to the surface of the leaf; wing- pads blend with 
general form of body, making a quite regular oval outline. 
Head broad; front margin gently rounded, distinctly lobed, 
terminates in gently rounded angles in front of the eyes, and 
furnished with a conspicuous fringe of wax-hairs. Antennae 
comparatively small, in first or second stages reaching only 
about half way to anterior margin. Eyes of usual shape, deep 
orange yellow. The wing-pads usually extend forward to the 
eyes, but sometimes reach the slightly indicated lateral angles 
of anterior margin of head. They gradually diverge poster- 
iorly, and the first pair extends slightly beyond the posterior 
coxae, but do not reach the posterior margin of the metathorax. 
The second pair are much smaller, extend over half their width 
back of first pair, and reach to the second or third abdominal 
segment. Abdomen broadly oval in outline, segments distinctly 
indicated. Anal opening larger than usual, conspicuous. The 
