Anatomy of the Male Genital Tube in Coleoptera. 503 



Silpha atrata (PI. XLIX fig. 48). 



Median lobe flattened, broad, with ventral side chitinous and 

 dorsal membranous ; median orifice at distal end ; median foramen 

 small, situate in the basal part of the ventral chitinous plate. 

 Lateral lobes broad at base, tapering to rounded point at apex. A 

 thin ring of chitin runs over the base of median lobe (bp) and 

 joins the bases of the lateral lobes ; this represents the basal-piece. 

 Internal sac large, rounded at the apex, with three large, round 

 diverticula at base (&), covered with long, fine hairs, thickest on the 

 dorso-basal surface. 



The median lobe is not consolidated to the basal-piece and can be 

 dissected away. 



The figure shows the apex of sac collapsed, the broken lines (c) 

 show the more normal shape. 



Silpha ohscura (PI. L figs. 49, 49a). 



Median lobe large, extending beyond the basal-piece ; the ventral 

 and lateral faces of the distal half chitinous, the dorsal side and all 

 the basal half membranous, except a small strip of chitin (a) extend- 

 ing from the median foramen (m/) towards the base. The median 

 orifice on dorsal side of tip ; the median foramen small, placed about 

 middle of ventral side. Lateral lobes fairly broad, curved at tips 

 and bearing a small knob, they are pressed closely to the latero- 

 ventral surface of the distal half of the median lobe. The basal- 

 piece is ringlike (bp). Internal sac large ; details not examined. 



Silpha jajjonica. 



Of the same type as S. atrata. The internal sac is flattened 

 horizontally and constricted in the middle, the dorsal surface is 

 covered with long, silky hairs. 



Silpha a7ialis (PI. L fig. 50). 



Though probably a different genus this is similar to the various 

 species we have already remarked on. The basal-piece is of rather 

 larger extent. Internal sac large with a large curved prong (a) on 

 each side near the base, basal part covered with short hairs, distal 

 part with granulated surface. 



Necrodes osculans. 



The aedeagus is of the Silpha ohscura type. The median lobe 

 broad, with distal half chitinous, especially on the ventral aspect, 

 the ventral half membranous ; the median orifice dorso-distal, and 

 the median foramen ventro-medial. The lateral lobes each broad 



