Anatomy of the Male Genital Tube in Coleoptera. 485 
Insecta that most nearly approximates to the Verte- 
brate penis is the internal sac, the knowledge of 
which has been almost nothing until its recent in- 
auguration by Jeannel. The median Jobe appears to 
be sometimes a complex or amalgamation of more or 
less individualised sclerites. (Cf. Hydrophilus.) 
LATERAL LOBES. Though a very suitable term for the 
parts in the various trilobe forms, it is inappropriate 
in cases where the projections (if homologous at all) 
are medianly situate. Paramere is quite as good as 
lateral lobes. Cornua (meaning cornua tegminis) is 
also not free from objection, and accessory process 
is rather cumbersome. Tegminal lobes might do if 
the term tegmen be itself accepted. 
BASAL-PIECE. Perhaps this term may stand till more is 
known about the cases in which it is two pieces, and 
those in which it appears to be absent. 
INTERNAL Sac. Probably the term Vesica might be prefer- 
able. But this part of the conduit is so protean in 
form and development that it might be better to 
invent a term indicating a structure that is pre- 
dominantly membranous. 
TEGMEN. This term seems convenient and adequate for 
the layer of sclerites external to the median lobe. 
The elytra of grasshoppers are frequently called 
tegmina, but we do not think this objection to our 
use of the term a serious one. 
CONNECTING MEMBRANES. This term cannot be com- 
mended. It gives the idea that the sclerites are the 
important structures. But the tube may exist without 
sclerites and is it then a connecting membrane ? 
Other terms (such as Prepuce) that have been used for 
various parts are totally unsuitable. We consider that it 
is premature to endeavour to establish permanent terms 
for the parts of the complex genitalia of Insects till the 
various Orders have been more thoroughly examined and 
compared. 
