THE GIANT EARTH-WORM OF GIPPSLAND. 25 
to that present in Megascolides. The work upon the latter was done quite 
independently of Brpparp’s, and the fact of the existence of a connection between the 
nephridia stated in a preliminary paper read to the Royal Society of Victoria in 
October, 1887. 
Bovrnez,* in Pontobdella, described a complete nephridial network with a pair of 
internal and external openings in each segment of the body. Brpparp has described 
a continuous network in Pericheta aspergillwm, and a network not continuous from 
segment to segment, or on both sides of the body in Acanthodrilus multiporus. In 
the former, the external openings are arranged in a row round the body; in the latter, 
they are very numerous and irregularly arranged in the anterior part of the body, 
less numerous, more grouped together, and having somewhat definite relationships to 
the sete in the posterior part of the body. 
In the anterior region of Megascolides the nephridial ducts are connected 
together, and branches pass in the body wall from the ducts of the nephridia on one 
side to those of nephridia on the other side of the dividing septa, forming a nephridial 
network. 
In the posterior region of the body, all the small nephridia in the ring are united 
by a network of ducts, and on the ventral surface on either side of the mid line runs a 
clearly marked single duct (d. Fig. 27), which opens into (1) the small nephridia on 
the ventral side in the posterior part of the segment, which are also connected with the 
nephridial network, uniting the ring of small nephridia, and (2) the large single nephri- 
dium anteriorly. This duct passes forwards and through the body wall immediately 
beneath the insertion of the septum appears to send forward a small prolongation into 
the next segment to the region of the small nephridia. From these the duct (d.) 
passes on again to the next large nephridium, and so on. The longitudinal duct in 
transverse sections is seen to lie internally to the ventralmost setz on either side. 
There is no doubt whatever as to the presence of the network uniting the smaller 
nephridia and the longitudinal duct on either side, into which the network opens, 
and which runs forwards to the large nephridium. The duct passing beneath the 
septum is finer and more difficult to trace, but Fig. 27 represents in diagrammatic 
longitudinal section what I believe to be the relationship of the nephridia on either 
side of the body. There is no connection ventrally between the nephridia of the two 
sides of the body, but the ring of small nephridia is continuous across the middle 
dorsal line. 
In the anterior segments there is thus present a communication between the 
external ducts of the nephridia at a number of points in the circumference of the 
body wall, whilst in the posterior segments this communication is limited to the 
ventral surface, and we then find that there is here in each segment a longitudinal 
duct connecting together (1) a ring of smaller nephridia, (2) a single larger 
nephridium. 
*QJ.M.S. July 1884, Plate 24, fig. 3, and Plate 26, fig. 8. 
