Anatomy of the Male Genital Tube in Coleoptera. 499 



sac are three irregular chitin plates (h) with a narrow strip of chitin 

 (a) running some way along the sac. Tliese appear to form guides 

 for the flagellum. 



P. mimus has a similar sac and flagellum which make ten complete 

 coils in the median lobe, like a coil of rope, and measure 20 mm. 



In PinopMlus where there is an enormously long sac 

 and flagellum, coiled up within the median lobe, it is not 

 likely that the sac is evaginated, but the flagellum is 

 thrust out and the basal part of the sac folded up like a 

 concertina bellows ; nor is it likely that the whole of the 

 long flagellum is everted, but the muscles acting upon the 

 coils cause it to operate like a coiled spring, the distal end 

 being thus thrust out and retracted when the muscular 

 pressure is relaxed. 



Othius fulvipen7iis (PL LIII fig. 65). 



Medium lobe bulbous with ventral distal edge projecting; median 

 orifice dorso-distal, median foramen small, ventro-medianal ; a semi- 

 membranous band running round bulbous part of median lobe. 

 Lateral lobes thin, separate, attached to median lobe on ventral edge 

 of median foramen. Internal sac large, apex forming two diverticula ; 

 on the larger diverticulum the ejaculatory duct opens ; a small 

 bilobed diverticulum on dorsal side and a pair of large diverticula 

 on ventral side ; between these last processes and the base are two 

 pairs of curved chitinous spines. 



Othius m.elanocejphalus (PI. LIII fig. 66). 



Very much like 0. fulvipennis, but the internal sac differs greatly ; 

 on each side near apex is a fine long diverticulum (a). 



Xantholiniis glahratus (PI. LIII figs. 67, 67a, Q7b). 



In this species the bulbous median lobe is of an extreme form, 

 being egg-shape, with a small membranous distal portion to which 

 the greatly reduced lateral lobes are attached. The median lobe is 

 formed of dorsal and ventral scleritea, round, and connected by a 

 semi-membranous band (m) ; the median orifice (mo) is at the distal 

 end, and the median foramen (mf) slightly in front (or basal) on the 

 ventral face. These two openings are separated only by a chitinous 

 plate (o) formed by the basal part of the lateral lobes which are 

 extremely reduced. The internal sac is three times the length of 

 the median lobe, tubular, and studded with large teeth, curved 



