Anatomy of the Male Genital Tube in Coleoptera. 513 



Oxysternus maximios. 



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 (PI. 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. 



Terctriosoma stebhingi. 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 Histeridae, Synteliidae, Sphaeritidae 

 and Niponiidae 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 form a tube. The 

 type is extremely different from Staphylinidae. But the 

 approximation to the Byrrhidae is clear. 



