Anatomy of the Male Genital Tube in Coleoptera. 499 
sac are three irregular chitin plates (b) with a narrow strip of chitin 
(a) running some way along the sac. These 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 Pinophilus 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 fulvipennis (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 melanocephalus (Pl. LIII fig. 66). 
Very much like O. fulvipennis, but the internal sac differs greatly ; 
on each side near apex is a fine long diverticulum (a). 
Xantholinus glabratus (Pl. LILI figs. 67, 67a, 670). 
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 sclerites, round, and connected by a 
semi-membranous band (m); the median orifice (mo) is at the distal 
end, and the median foramen (m/f) slightly in front (or basal) on the 
ventral face. These two openings are separated only by a chitinous 
plate (a) 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 
basally, 
