June, 1918 Bulletin of the Brooklyn Entomological Society 53 
Eosentomon (Fig. 86) the terminal portion of the phallus is com- 
posed of a pair of inner structures, the ewpenes “eu,” and a pair 
of outer parts, the so-called parameres “ pr.’ The ejaculatory 
66 9 
ducts empty through the wirga “va” at the end of the eupenes 
“eu” in Eosentomon (Fig. 86), so that these structures are 
doubtless homologous with the parts labelled “eu” and “va” in 
the primitive Dermaptera (Fig. 28). The so-called parameres 
“pr” of Eosentomon (Fig. 86) are doubtless homologous with 
the parameres “pr” of the Dermaptera (Fig. 28); but there is 
some question in my mind whether the structures usually termed 
parameres in Nicoletia (Fig. 95, ““pr’’) are entirely homologous 
with the parameres of the other insects mentioned above. The 
cleft phallus “pe” of Nicoletia (Fig. 95), however, is apparently 
homologous with the inner pair of structures “eu” of the phallus 
of Eosentomon (Fig. 86), as is also true of the two structures 
labeled “pe,” in the Ephemerid shown in Fig. 5, since the ejacu- 
latory ducts open through these structures. 
I am not certain that the structure labeled “va” in the Plecop- 
teron shown in Fig. 14 is the “virga” of the primitive Dermap- 
tera (1. e., “va” of Fig. 28) which is the chitinized terminal por- 
tion of the ejaculatory duct; and there is a possibility that the 
structures called postunci (or penis hooks) of the roach shown in 
Fig. 96, “pn,” may correspond to the virga “va” of Fig. 28 
although the ejaculatory duct does not appear to open through 
them; but until suitable material for determining this point is 
available, I have retained the separate designation postunci for 
the structures in the roach, etc. 
In the roaches and Mantids (Figs. 83, 91, 67, 68, and 77; and 
Figs. 70, 71, 75, 78 and 79) it is extremely difficult to determine 
which structures are the typical parts of the phallus of the primi- 
tive insects, so that it has seemed preferable to apply distinct terms 
to the parts of the insects in question, until their homologies can 
be more definitely determined. In these roaches and Mantids, 
there are two asymmetrically arranged lower lobes or sublaminz 
“sl” which may or may not be provided with terminal penis- 
hooks or postunci “pn.” There is a possibility that these lower 
lobes may represent the pair of inner structures “eu” of Figs. 28, 
86, etc., or the two lobes labeled “pe” in Fig. 5. 
