118 Annals Entomological Society of America  [Vol. VII, 
a little in front of its usual position. The innermost fibres 
of c nearly meet in the middle line, covering the origin of a. 
Toward the posterior end reduction is progressive to the 
last segment, and becomes extreme in the ninth, which however, 
is unmistakably a true segment. The fibres gradually go 
over to the rectus type, becoming simple and longitudinal, 
and gradually decrease in number, till in the ninth segment 
only five ventral ones are left. 
The ganglia are fused in the seventh segment more or less 
completely, but always the true seventh ganglion is recognizable 
with its usual nerves,—,the sympathetic nerves from the last 
spiracle run back united with the nerve for the eighth, as far 
as the incisure, then run normally to the spiracle and last 
wings of the heart. All the principal muscles are present, 
but a, f, g, h, i and E do not extend beyond the eighth acroster- 
nite, because of the disappearance of the pre and ante-costa 
of the eighth segment. The deep muscles are reduced, p and 
x appear clearly as longitudinal (oblique) muscles similar in 
character to I, Land Q, R of the dorsal region. ¢ also appears 
longitudinal, a suggestive fact, as in general it resembles more 
closely the fanlike transverse muscles, but z is evidently trans- 
verse. ais normal, m and q are undifferentiated, and clearly 
pleurosternal; d is normal, n and r extraordinarily shortened, 
while 6 (representing y) and 6 are also nearly simple— 
evidently the proleg is merely the small area enclosed by 
fi arid er. 
The eighth segment has the two normal nerves running back 
from its ganglion in the preceding segment. The first runs 
outside c, which apparently represents part of a of other seg- 
ments; it passes between f and g, defining them as usual. 
Muscles a toi and the corresponding dorsal ones are all reduced 
to the simple segmental type, M and 1, being connected with 
the spiracle, remain normal, but @ is simplified in front and 
its homologue behind is much reduced. The lateral muscles 
are perfectly simple, and the longitudinal ventral ones are 
reduced to a single set of sort fibres (p). 
In the ninth segment with the disappearance of heart and 
spiracle the sympathetic is also gone, but the two principal 
nerves are easily found, (sometimes with the first arising 
behind the second). The first runs between a and b, which 
latter has to serve for b, c, d, e, f, ff, and h of normal segments; 
