Anatomy of the Male Genital Tube in Coleoptera. 513 
Oxysternus maximus. 
Median lobe rod-like, dilated at the tip into a cleaver-shaped 
process. Basal-piece moderately long, slightly asymmetrical, with 
a large membranous area on one aspect, just anterior to its junction 
with the lateral lobes. Lateral lobes very long, coalesced on their 
basal portions to form a very hard tube, the apical two-fifths 
forming a half tube, or trough, at the basal portion of which is 
the articulation of the median lobe. The rod-like, very hard 
median lobe renders it pretty certain that the sac remains un- 
differentiated. The aedeagus is here a beautiful structure with 
very solid chitinisation. 
Hololepta elongata (Pl. LV figs. 81, 81a). 
The aedeagus is flattened and thin, the basal-piece more than 
two-thirds the length of the lateral lobes; the lateral lobes amal- 
gamated along the dorsal surface to the tip and along the ventral 
surface for the basal two-thirds. The median lobe is greatly reduced. 
Saprinus nitidulus. 
Median lobe small, only the tip visible. Lateral lobes very 
large, consolidated together along their entire length, with the tips 
slightly flattened and turned down; this forms a complete tube 
with an-opening at the tip on the dorsal side. Basal-piece very small, 
asymmetrical. Internal sac small, apparently not differentiated. 
Teretriosoma stebbingi. We are indebted to Mr. Lewis 
for the opportunity of examining this rare and interesting 
Histerid. The individual was in a very decayed con- 
dition and the preparation was not very successful, but 
it shows that this form departs from the other Histeridae 
we have examined by the shape of the lateral lobes, 
which are flattened divergent laminae. Their conjunc- 
tion with the basal-piece seems to be more intimate than 
usual, 
The four families Misteridae, Synteliidae, Sphaeritidae 
and Nipontidae are so closely related by the aedeagus, that 
they might form one family, in which the Histeridae would 
include the higher developments. Its characteristics are 
the existence of a basal sclerite having no power of move- 
ment over the median lobe, and extremely large lateral 
lobes more or less amalgamated to forma tube. The 
type is extremely different from Staphylinidae. But the 
approximation to the Byrrhidae is clear. 
