66 A. ©. OUDEMANS. 
mouth have each their own aperture, nearly terminal.) The 
passage through the cerebral ring and the communication with 
the median vessel, which only in the cesophageal region lies in 
the sheath, are similar to what occurs in all Hoplonemertea 
with cephalic loops. In the cesophageal region no transverse 
vessels occur, in the intestinal region, however, they do. The 
communication in the tail is normal. 
The nephridial system lies, in the cesophageal region, entirely 
above the nerve-trunks, and always has numerous windings, so 
that nearly always more than one transversely cut canal is seen 
in sections. If we bear the fact in mind that a winding canal 
must always show three, five, or seven sections, and if we than 
see in a slice four sections of canals, we must conclude that at 
least one of these canals is a branch. As I often observed an 
even number, so I suggest that there are many branches, as I 
have represented in fig. 7. The excretory ducts lie in the 
midst of the cesophageal region, above the nerve-trunks, 
and curve downwards, having ventral apertures. Fig. 42 
exhibits a section through the cesophageal region of Dre- 
panophorus. 
From the proboscidian sheath lateral sacs proceed between 
the intestine and the nerve-trunks, arranged in pairs and 
ranging from the ganglia to the end of the proboscidian sheath. 
McIntosh was the first (24) who observed this peculiarity of 
the sheath of Drepanophorus. He saw on sagittal sections 
openings through the lateral walls of the proboscidian sheath, 
and represents them, but without further tracing what these 
Openings are. He, however, concluded that these openings 
(stomata) form the connection between the vascular system 
and the proboscidian sheath. Hubrecht (35) recognised the 
true nature of these organs, calling them “membranaceous 
sacs.” I have exerted myself to trace, on transverse as well 
as on horizontal sections, these peculiar spaces. They are 
only blindly terminating tubes, sometimes very much dilated 
and at their extremities sac-shaped. They generally run with 
a downward curve. Only once I found a communicating 
branch (longitudinal) between two of these sacs. Their open- 
