MONILIGASTER GRANDIS, A. G. B. 333 
of Segment x1 and also to the ovary, this vessel supplies the 
dorsal region of the body-wall of Segment x. 
The ventro-tegumentary vessel of Segment v calls for special 
remark. After leaving the ventral vessel it runs outwards and 
forwards along the body-wall towards the dorsal region. The 
first branch runs to the salivary glands, the second penetrates 
the muscular layers of the body-wall; the next two branches 
come off at almost exactly the same spot; the one supplies 
the nephridium of Segment v, the other runs forwards, and 
on its way supplies the nephridia of Segments rv and 111. 
There are seven other branches, which all run forward and 
penetrate the body-wall. There are thus eight branches from 
each of these ventro-tegmentary vessels (those of Segment v), 
which run forwards in the body-wall of the anterior extremity. 
The ventro-tegumentary vessels of Segments Iv, 111, and 11 
are all small. | 
The ventral vessel comes to an end anteriorly in the region 
of the subcesophageal ganglion by giving off the ventro- 
tegumentary vessels of Segment 11, each of which gives off 
three main branches, supplying, doubtless, the prostomial 
and peristomial regions, and of course Segment 11. 
Dorso-tegumentary Vessels.—These are branches of 
the dorsal vessel connecting it with the peripheral networks. 
All the branches of the dorsal vessel anterior to the hearts, 
and one pair of those branches in each segment posterior to 
them, belong to this category. 
In the most anterior portion of the dorsal vessel they arise 
from this slightly irregularly, i.e. asymmetrically. 
In all other segments they arise regularly from the dorsal 
vessel immediately in front of the septum, which forms the 
anterior boundary of the segment in which they lie. 
All these dorso-tegumentary vessels which arise behind the 
hearts have similar relations. Each runs boldly outwards, 
unattached to any other structure, and appearing always as 
though the blood in it was under considerable pressure, and at 
about the outer seta line it bifurcates ; the two branches are 
really portions of the subneural system, and are coloured blue in 
