NOTES ON SOME AQUATIC OLIGOCHATA. 911 
The sperm-sacs are paired, and have the normal arrange- 
ment extending as far back as Segment xvi; there are three 
large eggs in xv, xvi, and xvir respectively (in one specimen 
one egg occupied the 16th and 17th segments). 
The spermatheca lies in Segment rx entirely; in St. 
gabretz it extends also into the next segment. I found no 
crystals, such as Claparéde found, in the spermatheca of St. 
heringianus. 
The characteristic penis differs from that of both the pre- 
vious species in shape and size. In St. Vejdovskyi it has a 
length just a little greater than half the width of the body 
(fig. 43). It is not so narrow relatively as that of St. gabrete ; 
it is not so pointed as in St. heringianus. In normal 
position its free end is on a level with the chet of Segment x1. 
The nephridia have a very peculiar arrangement. The 
first nephridial funnel lies in Segment v1, just in front of the 
posterior septum; the tube passes backwards with only slight 
undulations and coils as far as the middle of Segment x, and 
then returns alongside itself into Segment vir, where it opens 
externally in front of the ventral chete. 
The second nephridial funnel lies in normal position in 
Segment x11; its external pore is in xs, and the looped tube 
passes backwards as far as the hinder part of Segment xv. 
The third funnel is in Segment xv, the nephridiopore in xv1, 
and the loop lies wholly in this segment. This is the normal 
condition for the following nephridia; but I observed one case 
in which the tube passed through two segments. 
This condition of the nephridium is very similar to that 
described by Vejdovsky for Phreatothrix, and is unknowi 
elsewhere amongst the Oligocheta. ‘The structure of the 
nephridium agrees with Claparéde’s figures and description, 
although in that species he states (p. 265) that the first 
nephridium lies in Segment vi1; that there are none in viizr, 
IX, X, XI, or x11, and that they reappear in x1i1. 
The length of St. Vejdovskyi is about an inch; none of my 
specimens exceeded this length. In colour they are bright 
red, with a tendency to orange; but the colour is much less 
