352 ALFRED GIBBS BOURNE. 
face of Septum x-x1, while no rudimentary genital organs 
form in any other segment. The “ ciliated rosette” develops, 
I believe, from the epithelium of this septum just ventrad of 
the testis, and afterwards, together with some of the muscles 
of the septum, grows round to enclose the testis and form the 
sperm-sac. The development of the sperm-duct I have not 
yet been able to make out. The wide mouth of the oviduct is 
in the adult nothing but a specialised portion of the septal 
wall. So that there seems to be in Moniligaster no connec- 
tion between genital ducts and nephridia. 
With regard to the relation of prostate to atrium I agree 
entirely with Benham (14), but I find that each gland-cell in 
the prostate opens by its own duct into the atrium, that it is, 
in fact, merely an enlarged cell of the atrial epithelium, so 
that I do not see why we should use the term ‘ multicellular 
gland.” The ccelomic epithelium is always to be found outside 
the other structures, in the form of pavement cells easily 
demonstrated by the use of silver nitrate. 
Systematic Account of the Genus Moniligaster. 
Before describing any other species! I shall discuss the value 
of the various characters for systematic purposes, taking ac- 
count of my own observations only. 
Colour has a certain value ; there are groups of species with 
pigment in the body-wall (figs. 6—10) and groups with little 
or no pigment (figs. 3,4), but the exact colouring varies much 
in some cases within the species (figs. 8—10). 
Size has some importance as there is great variation, but 
the condition of the worm when measured must be estimated 
(see above, M. grandis—size, p.307),and the specimen must be 
1 Out of the thirteen species described below, I place three (M. grandis, 
M. naduvatamensis, and M. nilamburensis) in one group and call it 
in the following account the M. grandis group; three (M. ophidioides, 
M. robusta, and M. sapphirinaoides) in another group and call this 
the ophidioid group; two (M. pellucida and M. uniqua) in another 
group and call this the pellucid group; the other species I do not group 
together in any way. 
