256 
FRANK E. BEDDARD. 
somewhat contorted ; the latter are narrower tubular organs 
exactly resembling each other (fig. 7). 
An examination of these glands by transverse sections shows 
that they all open on to the exterior at a corresponding point 
in the three segments ; the external apertures of these glands, 
in fact, correspond in position to the innermost of the ventral 
pair of setae. I find, however, that in these three segments, 
viz. 17, 18, and 19, the ventral pair of setae are altogether 
absent, although they are present in the neighbouring seg- 
ments. The dorsal pair of setae are as well developed in 
segments 17, 18, and 19 as in any others. 
It is very common to find some modification of the setae in 
the segments which bear the male generative pores, such as, 
for example, the bundles of elongated setae in Acanthodrilus, 
but I am not acquainted with any other instance (except Eu- 
drilus) in which the setae entirely disappear on these segments 
(figs. 16, 17). 
The anterior pair of glands (figs. 7, \6.pr.), those which occupy 
segment 17, and which are distinguished by their greater size 
and greater opacity, are the real atria ; that is to say, it is these 
glands alone which are connected with the vasa deferentia. 
These glands have much the same structure as in other Earth- 
worms; the very narrow lumen is surrounded by a layer of 
columnar cells ; outside these is a mass of glandular cells, the 
exact relations of which the condition of the material does not 
enable me to state positively. Apparently these cells resemble 
very closely the corresponding cells in the prostate of Eu- 
drilus. Outside is a delicate sheath containing blood-vessels 
which send off branches among the gland-cells. The atrium 
comm unicates with the exterior by a slender but thick-walled 
muse ular duct ; this duct is at first much contorted, but when 
it enters the body wall is perfectly straight; its course through 
the latter is oblique, the external orifice being placed nearer to 
the ventral median line than the point where the tube enters 
the body wall. 
The tubular glands of segments 18 and 19 (figs. 7, 1 7,pr.') 
are straight, and not contorted like the glands of segment 17, 
