Anatomy of the Male Genital Tuhe in Coleoptera. 571 



reaching beyond the ends of the median struts, with a stout, curved, 

 spine-like flagellum at the apex and a large diverticulum (a) below 

 it. 



Polycleis pluvihcus. 



Median lobe well chitinised, tubular, slightly flattened and 

 curved ; ventral edge of median orifice projecting beyond dorsal 

 edge and bluntly pointed ; median struts small and slender, only 

 half as long as the median lobe. Tegmen forming a ring-piece 

 with a pair of small delicate projecting lobes on dorsal aspect and 

 a slender central strut on ventral aspect. Internal sac contained 

 within median lobe. 



With the increased chitinisation of the median lobe there is 

 here a reduction of the median struts. 



Brachycerus aptems. 



Median lobe forming a short flattened tube, with the ventral edge 

 of median orifice projecting beyond the dorsal edge and pointed ; 

 median struts large. Tegmen forming a ring-piece with lateral 

 lobes consolidated into a cap-piece on dorsal aspect ; central strut 

 on ventral aspect large. Internal sac long with armature which we 

 have not examined. 



Behts bidentatus (PI. LXXVI fig. 223). 



Median lobe forming a straight chitinous tube, with a pair of short 

 median struts ; median orifice at apex. Tegmen forming a wide 

 ring-piece with a long narrow cap-piece ; central strut large. Internal 

 sac long, projecting' some way beyond the median struts. A fine 

 chitinous tube (a) projects through the apex of the sac, and ends in 

 a membranous flagellum (fg) ; the chitinous tube (a) appears to have 

 the power of being moved through the apex of the sac. The apex of 

 the sac is supported by two crescent-shaped sclerites (fe), one on each 

 side of the tube. The dorsal and ventral aspects of the internal 

 sac are supported by two chitinous plates from near the apex to the 

 base. 



The long, slender sac with the flagellum at the apex 

 recalls the highly specialised flagella and long sacs of the 

 Brenthids. 



Sphenophorus ohscuriis (PI. LXXVI figs. 224, 224a). 



Median lobe forming a semi-chitinous tube, supported along each 

 side by a chitin strip (a), the median orifice is at the apex on the 

 dorsal face and is supported by a chitinous ring. From the basal ends 



