Anatomy of the Male Genital Tube in Coleoptera. 589 
narrow strip of membrane ; their inner aspects flattened and ad- 
pressed. Median lobe apparently not passing between the lateral 
lobes. 
This is very different from any other of the forms 
we have examined. The relationship of the median lobe 
and the lateral lobes would appear to be very unusual, 
but having only one specimen at our disposal this is not 
very clear. 
Rhizotrogus solstitialis. 
Of the same type as Melolontha. Median lobe medium size, 
membranous, supported by two thin sclerites. Lateral lobes large, 
broad, joined together to near their tips and forming a tube. 
Basal-piece not quite so long as the lateral lobes, chitinous on dorsal 
side but membranous on ventral. Internal sac large. 
Anoxia ortentalis. 
Median lobe small, chitinous on each side, with two long 
median struts. Lateral lobes very large, long and curved at 
points ; on ventral side they are consolidated for about one-fourth 
of their length near the base; on the dorsal side the basal three- 
fifths are consolidated together. Basal-piece tambour-like, some- 
what shorter than the lateral lobes. Internal sac fair size, no 
chitinous armature. 
Melolontha vulgaris. 
Median lobe fair size but membranous, except for a narrow 
strip of chitin along each side, proceeding into basal-piece as two 
median struts. Lateral lobes long, narrow, and curved, with the 
tips slightly expanded ; joined together at their base on ventral 
and dorsal sides with a membranous connection nearly to their 
tips. Basal-piece ‘tambour-like, forming a large curved sclerite on 
dorsal side, the ventral side membranous. Internal sac large and 
complex, covered with small hairs but bearing no chitinous 
armature. 
The student should refer to Straus-Durckheim’s immortal 
work on Melolontha. It will give him a good idea of the 
genital tube in Coleoptera, as well as a knowledge of 
the details of this species. He uses the term “ tambour’ 
for the large basal-piece of the aedeagus, and we have 
used it also in the sense of a general resemblance to 
Melolontha in the form of this part. The tambour shape 
does not exist in Z’rox, and Amphicoma shows a very great 
modification of it. 
TRANS. ENT. SOC. LOND. 1912.—PART III. (DEC.) RR 
