474 
LEPIDOPTERA. 
near to the thick edge of the wing, there is generally a 
brown dot. The hind wings are much paler than the others, 
and have a small brownish dot in the middle. The color 
of the body is tbe same as that of the fore wings ; and the 
legs are ringed with buff and brown. The wings expand 
one inch and three quarters. The body of the female is 
grayish or yellowish white ; it is sprinkled on the sides 
with black dots, and there are two square black spots on 
the top of each ring, except the last, which has only one 
spot. The front of the head is black ; and the antennaj 
and the legs are ringed with black and white. The tail is 
tipped with a tapering, jointed egg-tube, that can bo drawn 
in and out, like the joints of a telescope. Exclusive of this 
tube, the female measures about half an inch in length. 
The eggs are beautiful objects when seen under a microscope. 
They are of an oval shape, and pale yellow color, and are 
covered with little raised lines, like net-work, or like the 
cells of a honeycomb. 
As these span-worms appear at the same time as canker- 
worms, resemble them in their habits, and often live on the 
same trees, they can be kept in check by such means as are 
found useful when employed against canker-worms. 
Probably more than one hundred different kinds of Geom- 
eters may be found in Massachusetts alone. Seventy-eight 
are already known to me. Some of these are small, and 
arc not otherwise remarkable ; some are distinguished for 
their greater size and beauty in the moth state, or for the 
singularity of the forms and habits of their caterpillars. 
None of them, however, have become so notorious on ac- 
count of their devastations as the species already described. 
4. Dei.ta-Motiis. ( Pyralides .) 
The Pyralides of Linnaeus are nearly akin to the Ge- 
ometers. Latreille called them Dcltoides , because the form 
of the moths, when their wings are closed, is triangular, 
