262 NEW YORK STATE MUSEUM 
hamules. Both the first and the second are remarkably lobed, 
hairy and chitinized. The first has reached the extreme in 
regard to its bilobed condition. The second hamule has a 
sharp, strong prong pointing anteriorly or in the opposite di- 
fection, tom the lobes Tor athe sis pain tnemantertoram | aimatincamets 
plainly seen anterior to the hamules with the framework in 
the same position as in other forms. 
We may, I think, assume here that these figures represent 
a developmental series in respect to the production of the first 
pair of hamules. 
Recapitulation of the important points in the foregoing 
paper: : 
t In Anisoptera the penis is found upon the 3d abdominal seg- 
ment, while in Zygoptera it is found on the 2d. It seems probable 
that the penis in Zygoptera is developed from the 2d segment, while 
that in Anisoptera is developed from the 3d and extended upon 
the 2d. However, evidence from embryology is needed here. 
2° The supporting framework in both suborders is built on 
the same plan. 
32 The situation of the posterior or second pair of hamules 
is homologous in the suborders, as well as the situation of the 
‘seminal vesicle. 
4 In Zygoptera only one pair, the posterior, of hamules is 
found unless we assume that the peculiarly developed posterior 
lobes of the anterior lamina here, are to be taken as hamules. 
5 No sheath of the penis is found in Zygoptera homologous 
in position to that of Anisoptera, but we may assume that the 
chitinized. structure between the posterior lobes of the anterior 
lamina‘ serves the’ same function as the sheath in Anisoptera, 
because of its location before and over the penis. 
6 The sheath in Anisoptera and the penis in Zygoptera are 
in homologous positions, that is, directly upon the anterior por- 
tion of the framework which passes across below them. 
“7 Evidence seems to show that the anterior lamina, first 
pair of hamules and the anterior portion of the framework, 
that is, the part extending under, and attached to the lower 
surface of the anterior lamina, are developments of the sternum, 
while all other structures on segment 2d come from the sternellum. 
8 The Libellulinae among the Anisoptera seem to show the 
least specialized male genital apparatus, while it is difficult to settle 
which is so among the Zygoptera. The extreme in specialization of 
these parts is perhaps found among the Gomphidae. 
