604 Mr. D. Sharp and Mr. F. Muir on the Comparative 
must admit that the term is not a good one. The part in 
question is highly complex. It is in fact the layer, or 
layers, of the tube of which sclerites of the aedeagus form 
a large, or the larger, part. 
The sclerites on the phallic portion of the genital tube 
form two groups. (1) Those situate on the distal portion 
of the tube (furthest from the body wall), which we call 
the median lobe (fig. 239, 5-4), and (2) those situate 
nearer the base, which we call the tegmen (3-2). The 
membrane between these two groups of sclerites we term 
the first connecting membrane (4-3), and the membrane 
at the base, joining on to the body wall, we term the 
second connecting membrane (2-1). The median lobe, 
together with the tegmen, we term the aedeagus. 
The point where the genital tube is reversed (5-d) we 
call the median orifice, and the lumen at the base of the 
median lobe (4—to corresponding spot below) we call the 
median foramen. Similar terms could be applied to the 
tegmen, but we have not found them necessary for our 
descriptions. 
Having thus given a description of the four parts of 
the tube, we now give remarks as to the structures of each 
of the four divisions. 
The second connecting membrane (or prephallic portion 
of the tube) varies in extent according to the size and 
shape of the aedeagus. In certain cases (1. e. Laccobiws and 
Sphenophorus) it is chitinised in part, and forms a covering 
round the aedeagus. At, or near, the base there is in 
many forms a chitinous rod with one or two prongs at the 
end, embedded in the membrane. This is the ‘‘Stengel” 
of Lindemann, “ Rod” or “fork ” of Hopkins, and “ Spiculum 
gastrale” of Verhoeff. Hopkins considers it as represent- 
ing the ninth sternite. A comparison of this in the various 
families would be of great interest, but would entail a 
study of the body segments, a task beyond the scope of 
this memoir. We have therefore left it out of consideration. 
The phallic portion of the tube is the one that has 
chiefly attracted the attention of coleopterists. It consists 
partly of membrane, partly of sclerites, and there may be 
most extreme differences in the chitinisation of its different 
parts, excessively hard chitin being continuous with delicate 
membrane. We have already explained that we call the 
sclerites in question the aedeagus, and that this consists of 
two parts, viz. median lobe and tegmen. 
