258 
FEANK E. BEDDAED. 
elsewhere (7) to the fact that the diverticula of the spermathecse 
in Lumbricidae are of different minute structure to the sper- 
mathecas, and are usually occupied by the bundles of sperma- 
tozoa which are absent from the spermathecse themselves. 
Nephridia. — The excretory system of this worm, as of so 
many others, differs in different regions of the body. Professor 
Spencer has called attention, in a paper (28) to which I shall 
have again to refer, to the fact that the nephridia of Megas- 
colides are different in the anterior and in the posterior regions 
and of the body ; this is also the case with Pericliseta (p. 262) 
and Urochaeta (p. 246); and the same condition occurs in 
many genera (e. g. Microchaeta and Thamnodrilus) in 
which the nephridia consist of paired tubes, each with a single 
coelomic funnel and external pore. 
With regard to Megascolides, Spencer points out that the 
nephridia of the anterior segments present more primitive 
characters than those of the posterior segments, where they 
first begin to be modified. This statement appears to hold 
good (as I have already pointed out) in Acanthodrilus, and 
the facts which I shall bring forward in the present paper 
show that in Perichaeta the nephridial system of the pos- 
terior segments is more modified than that of the anterior 
segments. In Urochaeta it is only in the anterior segments 
that a single nephridium has more than a single ciliated 
funnel. With regard to such genera as Microchmta and 
Thamnodrilus, it is difficult to say that the anterior ne- 
phridia are in any way more primitive than those of the 
posterior segments. 
In Dichogaster the same generalisation with respect to the 
nephridia appears to hold good. I am unable, however, to 
give so complete an account of the nephridia as I could have 
wished. The first five segments are occupied by a large 
nephridium, which evidently corresponds to the large anterior 
nephridium of Acanthodrilus multiporus and A. annec- 
tens. I could not find the funnels of this organ (if they are 
really present), nor could I find any very decided evidence of 
its being a branched gland. I am rather inclined, however, to 
