PACIFIC COAST OLIGOCH MTA. 71 
anterior septum. In Phwnicodrilus taste, however, the spermatheca lies always flat 
pressed against the ventral side of the body-wall, and is of sufficiently large size to reach 
as far backwards as to the posterior septum between ix and x, which makes it about 
equal in length to the diverticula of the cesophagus (fig. 1, spth.) The lower part 
of the spermatheea is as usual more muscular than the free end, which in this species 
is more or less, though always shallowly, lobed, showing a large number of incipient 
diverticula irregularly formed and arranged. The spermatozoa are found principally 
in these warty diverticula. 
Testes are very long and situated as usual in x and xi. The posterior one at 
least, and propably both pairs, connect with the sperm-sacs in the same somite. 
Sperm-sacs are arranged as in some species of Oenerodrilus. They are all 
paired. The anterior pair in ix is attached to the posterior septum of that somite. 
This pair is very much lobed, the lobes being more in number and in shape more 
round than in any species of Ocnerodrilus, the pair resembling two bunches of large 
grapes, completely filling the whole available space in the somite, especially above the 
diverticula and the cesophagus. The sperm-saes in x and xi are less or hardly lobed, 
connecting with the the testes below, the latter, being long, slender and not branched, 
reach across the somite and joining the sperm-saes in the posterior part near the sep- 
tum. The sperm-sacs in xii are connected directly with those in xi, but otherwise 
attached to the anterior septum of somite xii. This pair of sperm-sacs are lobed but 
not as much so as those in ix. 
There are two pair of ciliated rosettes in x and xi, and two pair of spermducts 
as usual leading from them. The spermducets join, as is generally the case, forming a 
single strand which runs close to, but a trifle more dorsally, than setze 2, until somite 
xvii is reached. In this somite each spermduct enters a small muscular atrium deyoid 
of prostate, and entirely confined to the longitudinal layer of the body-wall. As soon 
as entering the body-wall and this muscular chamber the two lumens of the spermduct, 
which until now had been separate, fuse together and enter the muscular chamber as 
one single duct. 
As atrium I consider a small muscular chamber entirely confined to the body- 
wall, in which the spermducts open. This chamber is, however, devoid of any 
glandular cell prolongation such as we are accustomed to find in Oenerodrilus, and 
ordinarily it ends where the spermducts enter, which is at the upper end of the layer 
of the body-wall. The atrium itself consists of an inner layer of epithelial cells, 
which at the very pore are much larger and furnished with larger nuclei, but which 
gradually decrease in size as they approach the place where the spermducts enter. 
This layer is a direct continuation of the hypodermal layer of the body-wall. An 
outside layer again consists of fine muscular fibres with smaller nuclei directly con- 
tinued from the transverse muscular layer of the body-wall. We see thus that this 
short chamber might in reality be nothing but the remnants of a degenerated atrium, 
or rather remnants of the lower muscular part of a degenerated prostate, which gland- 
ular prolongation has disappeared. That this is the case I judge from the structure 
Memorrs, Vou. II, 4. February, 1895. 
a 
