REPORT OF THE STATE ENTOMOLOGIST 1907 257 
marked by two peculiar folds, one attached directly to the lobe 
at a@ and the other forming what appears as a sheath yv for 
the penis p. Attention was called to this particular structure 
in figure 18 (d). It is suggested that perhaps the large posterior 
lobe of the lamina indicated at a may function as a hamule, 
iike the first pair of hamules present in many of the Anisoptera. 
Letter e shows the anterior portion of 
the framework which is connected 
with vw the posterior portion at h or 
the hamule. The penis is supported 
directly by e and in a position exactly 
corresponding to the sheath in Anisop- 
tera. Only its base is shown, with 
the recurved tip cut off. f shows a 
line just back of the hamule h ap- 
parently separating the hamule and Pie BE 
the posterior portion of framework v from e the anterior portion. 
‘In (1) one may note the condition found in the Anisoptera. 
The well developed hamule h resting on the framework with 
its prominent hooked end extended posteriorly. The second h 
refers to another structure developing from the anterior lamina 
1 and functioning where well developed as the first or anterior 
pair of hamules. s is the sheath for the penis (penis not shown 
in the figure: it is attached to segment 3 but extends forward 
well over segment 2.) g is a structure peculiar to the Libel- 
lulidae, already referred to as the genital lobe and no doubt func- 
tioning in copulation. 
The greatest difference to be noted in these two figures is 
in the location of the penis. In Zygoptera we find it on seg- 
ment 2 and in the exact position occupied by the sheath in 
Anisoptera. 
Let us now turn to the anterior portion of the second abdom- 
inal sternite. In figure 24 there are several anterior laminae of 
Anisoptera, each showing quite clearly that portion of the lamina 
which the writer holds has developed into the anterior pair of 
hamules. 
In (a) the anterior lamina of Didymops is shown. I is the 
lamina, with h the highly chitinized first pair of hamules well 
developed and slightly reflexed on their edges, no doubt a de- 
9 
