232 Mr. F. Muir on the Male genitalia of Merope tuber. 
This organ (fig. 6) consists of two pairs of small processes, 
an anterior or ventral pair (h) which are small and pointed 
and have their bases continued as two membranous flaps (7). 
There is a round sclerite (4) at the base of each of these 
processes, to which is attached a long strut; the posterior 
or dorsal pair are larger and rounded at apex (g). A strong 
chitinous apodeme (/) connects these processes with a 
strong, chitinous U-shaped body (f), which is attached to 
the framework round the orifice in the fork of the coxites. 
This internal structure gives attachment to the muscles 
which actuate the organ. The opening of the ejaculatory 
duct lies near the base of the anterior processes. 
The penis of many insects is complex and our knowledge 
so slight that to attempt to homologise the various parts 
composing it is, at present, only a confession of faith and 
not a statement of fact. In certain Homoptera (7. e. 
Issidae, Ricanidae, Flatidae, Lophopidae), besides the 
paired genital styles (and probably a second pair amal- 
gamated with the pygofer in the Fulgorids but found free 
in Tettigonidae, Membracidae and some Cercopidae), we 
find a penis composed of three tubes one within the other. 
The outer or the middle tube often bears complex appen- 
dages. In Coleoptera and some Diptera (7. e. Tabanidae) 
we find complex organs situated on the internal sac at the 
opening of the ejaculatory duct. When discussing the 
homologies of the penis it is therefore necessary to consider 
all these structures. 
Although the coxites and styles are greatly developed 
in this species of Merope, the rest of the genitalia are not 
so specialised as in many of the Mecoptera. 
The coxites in this species would appear to be homo- 
logous with the dorsal valvulae of the female ovipositor, 
and the structure between them would then represent the 
inner valvulae. It is this latter structure which apparently 
undergoes such strange developments and forms the penis, 
or entirely disappears and leaves a membrane on which 
the ejaculatory duct opens. 
I have to thank Dr. R. J. Tillyard for the pleasure of 
dissecting this interesting insect. It is not every entomolo- 
gist who would allow such a rare specimen to be cut up. 
