Anatomy of the Male Genital Tube in Coleoptera. 569 
(d) with the sides curved up, and another plate (e) below it, and 
this is produced into a blunt median keel (f); there is a large 
diverticulum (y) as in Aromia. A considerable part of the sac is 
beset with small, chitinous teeth. 
Among the forms of this large family that we have 
examined there is a great uniformity of type, the median 
lobe having the orifice at the tip and extending along the 
side, the sclerites on the dorsal and ventral aspects being 
separated by a membrane running along each side, from 
orifice to foramen; the base of median lobe prolonged 
into two struts; tegmen ring-shaped, with a divided pro- 
jecting process, the division generally very deep; internal 
sac long, projecting into the body forwards beyond the 
median foramen in the state of repose. 
It is in the great development of the sac, and the diver- 
sities in its armature that we must seek the peculiarities 
of the family. Parandra, so far as the genital tube is 
concerned, appears to be the lowest form; in it we have 
found no specialisation of importance. A general resem- 
blance between the tube of Parandra and that of Cucu- 
joidea is evident at first sight (compare Parandra, fig. 
219 with Cucujus, fig. 97, or Passandra, fig. 96). In the 
section phylogeny we have shown reasons for supposing 
that this general resemblance may be deceptive. 
We have examined various other Cerambycidae without 
finding anything to make it necessary to increase the 
length of this memoir by including them. But there is 
one point we must mention briefly. Bordas has pointed 
out that in certain Cerambycidae there appear to be present 
two ejaculatory ducts. In other words that the stenazygos 
is wanting. We also have observed this fact in Gnoma 
(PI. LX XV fig. 220) and in some species of Monohammus 
(Pl. LXXVI figs. 221 and 2212). 
That this fact is of much morphological importance is 
not clear to us. It may perhaps be due to the great 
extension of the sac (or eurazygos). And in fact in another 
closely allied species of Monohammus we have found a 
distinct stenazygos. The structure as it has appeared to 
us in Monohammus longicornis is shown in Pl. LXXV fig. 
221, and in 221a where the sac is everted. It is then 
seen to be studded with small spines, and bears two 
diverticula, thus acquiring a singular resemblance to the 
head of a dog; and it will be seen that there is a short 
