STRUCTURE OF THREE NEW SPECIES OF EARTHWORMS. 119 
dant muscular fibres. I have, however, myself been able to 
show, in a paper recently communicated to the Zoological 
Society (6), that these differences only mask a fundamental 
similarity, and that the minute structure of the glands in 
Eudrilus closely corresponds to that of the prostate glands in 
Acanthodrilus. It can be hardly doubted that the “sausage- 
shaped glands” of Eudrilus are the real homologues of the 
prostate glands in Acanthodrilus and Pontodrilus. 
In Criodrilus (Rosa, Benham) and Allurus (Beddard) 
the termination of the vas deferens is furnished with a glan- 
dular structure, which is not only different in structure from 
the glands that have been already referred to, but is also unlike 
in general aspect. 
Finally, in Moniligaster (Beddard, 4) the male efferent 
duct opens into a minute pouch, larger in M. Deshayesi 
(Perrier 15 ) and M. Houteni (Horst 14 ) than in M. Barwelli, 
which bears a certain resemblance to the prostate of Acan- 
thodrilus, but which, as will be seen hereafter, differs in 
certain important structural features. 
The questions which I shall attempt to answer are : (1) Are 
these various glandular bodies appended to the vasa deferentia 
homologous with each other ? (2) What relation do they 
bear to analogous structures in the aquatic Oligochseta? 
Moniligaster exhibits a condition of the efferent ducts, 
which is remarkably different from that of all other Earth- 
worms. In a species (M. Barwelli) recently described by 
myself (3) the vasa deferentia, as in many Limicolse, only 
occupy two segments; there is only a single vas deferens 
on either side, the internal funnel of which is situated in one 
segment, and the external aperture on the following segment. 
The vas deferens opens on to the exterior in common with a 
glandular structure, which I have called a “prostate” in my 
account of the anatomy of this worm, and compared with the 
prostates of other Earthworms. 
The structure in question is seen by an examination of 
transverse sections to contain a wide cavity which opens on to 
the exterior ; the cavity is lined with a layer of large glandular- 
