WILLIAMS: HABITS OF SCUTIGERELLA. 
481 
shown in plate 38, figures 10 and 11. These are respectively a surface 
view of a small portion of the chorion and a profile view of a section 
through the chorion. The section indicates that the chorion is non- 
cellular in its structure. 
The egg envelope is opaque, or at least only slightly translucent, 
and of a special pearly whiteness so that the eggs are exceedingly 
beautiful objects. 
Incidentally figures 4 and 5 of plate 37 show the egg envelope while 
they illustrate the larvae during the time of freeing themselves from 
the envelope. , 
In handling the eggs, a few were accidentally injured and these 
exuded drops or spheres of perfectly clear liquid and left the membrane 
of the egg much shrunken. Such eggs never hatched. 
Larvae. 
The young of the S. immaculata when entirely freed from the egg 
envelope, varies from 0.75 mm. to 1.5 mm. in length and is about 0.5 
mm. wide. After the severe struggles to escape from the eggshell 
the animal is quiescent. It will, however, move if disturbed and seek 
a more protected crevice in the wood or earth on which it is resting. 
The young has usually six joints in the antennae (pi. 36, fig. 1-3). 
It has ten dorsal shields or scutes and seven pairs of legs. In some 
specimens the buds of the 8th pair are distinctly visible ventral to the 
tenth dorsal scute. The legs (shown in pi. 36, fig. 1) are seen to arise 
from beneath dorsal scutes 1, 3, 4, 5, 7, 8, 9. In figure 3 (pi. 36) of 
the ventral view one cannot see the relationship the legs bear to the 
dorsal scutes, but in certain places the boundaries of the ventral plates 
are visible. The top view of a specimen (pi. 36, fig. 2) shows the 
scutes and shows that the trochanters of the legs point toward an origin 
from beneath the same scutes as were indicated in the side view. The 
varying positions of the animals change the relationship between the 
scutes and the legs somewhat so that these may not always correspond. 
As the dorsal scutes are not homologous to single tergites according 
to Sinclair (’95), it is possible that variation in their widths may aid 
different positions of the body in changing the seeming relationships; 
of the legs and scutes. 
The first leg on each side has but four joints while there are five 
joints in each of the other six pairs of legs. Excepting the first pair of 
legs again, the other pairs are all about the same length. All are used 
