Marshall—On the Anatomy of the Dragonfly . 757 
The genae (fig. 1 , G), including that part of the epicranium 
in front of the eyes, are small and barely seen from an an¬ 
terior view. Each is but a small piece at either side of the 
clypeus and is in part hidden by the posterior clypeus and the 
mouth parts. 
The epicranium, besides the parts already described, ex¬ 
tends back of the eyes and over the posterior surface of the 
head. The largest part of the surface at the back of the head 
is covered with dark brown chitin; this area lies between the 
occiput above and the occipital foramen below and is divided 
into right and left parts which are connected by a wide bridge. 
In a lateral view of the head a small piece of this part of the 
epicranium is seen to lie along the posterior margin of each 
eye (fig. 2, Ep.). Just where, at each side, this piece turns 
inward to cover the posterior surface of the head there is, 
extending from dorsal to ventral margin, a band of setae 
(seen in fig. 2) ; these, for about one quarter of the distance 
from the dorsal boundary, are longer than at any other place. 
A lateral view of the head shows two light areas (drawn with¬ 
out stippling in figure 2), one near the middle, the other ven¬ 
tral. 
The gula (fig. 3, Gu.) consists of two portions; the basal 
piece 2mm wide, 1.25mm high, is somewhat rectangular in 
shape; from the upper corners of this piece arise two slight¬ 
ly curved arms which extend up to the occipital foramen. 
‘ The labrum (fig. T, Lb.) is 2.75mm x 1.20mm; it is slight¬ 
ly convex on the outer and concave on the inner surface, the 
greatest convexity is medium near the upper margin. On the 
outer surface, along the free margin, runs a strip, darker in 
color than the rest and having the cuticula thicker. At the 
upper corners this strip turns inward and extends nearly half¬ 
way to the median part of the labrum (this part is stippled 
in fig. 1, Lb.). Along and near the free margin are a number 
of setae; all of these are slightly curved and, in most of them, 
the concavity faces the median axis of the labrum. Along 
the upper surface are other curved setae, these are not so long 
as the marginal ones. The labrum moves very freely on the 
