214 FRANK E. BEDDARD. 
became continuous with the nephridium, and at that point 
gave off a duct which penetrated the body-wall and apparently 
opened on to the exterior, though I did not succeed in dis- 
covering the actual pore. Following the duct back, the 
longitudinal duct was found to vary in calibre from place to 
place; it was sometimes so reduced as to be very nearly 
invisible; at other times it became of much greater calibre 
than the average. In these places it seemed as if the duct 
formed a kind of rete. In the one segment I counted three 
or four of these retia; in the same segment three or four 
branches arose from the longitudinal duct to apparently reach 
the exterior. At the point where the septum was attached to 
the body-wall the nephridial duct penetrated still deeper within 
the longitudinal muscular coat. When the septum lifted away 
from the body-wall, the inner of the two longitudinal ducts was 
found to have resumed its original position. Immediately after 
the septum a branch was given off from the vessel which, 
penetrating into the body-wall, passed round the circumference 
of the body, ultimately joining the outer of the two longitudinal 
ducts. I confess that the actual junction was not observed, 
but the tube was traced up to a very minute distance away 
from the second of the two longitudinal vessels; in front of 
this there is a connection by way of the peritoneum—a duct, 
that is to say, runs from one longitudinal duct to the other in 
the peritoneum. Here, again, I was not able to find the actual 
opening at both ends; but I have no doubt, from the appear- 
ances presented, that this takes place. The second longitudinal 
duct—that running on a level with the outer pair of setee—is 
not dilated, and shows no such retia as the inner duct; nor 
does it appear to give off any branches penetrating the integu- 
ment and reaching the exterior; in other segments, and more 
particularly in the region of the body occupied by the clitellum, 
I could not find the connection of the nephridia from segment 
to segment, such as undoubtedly occurs in some, at any rate, 
of the anterior segments. The nephridial system of this 
species, therefore, is constructed on the plan of that which 
characterises the genus Libyodrilus, but is in a less differ- 
