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FRANK E. BEDDARD. 
looking cells ; outside these again are abundant muscles fol- 
lowed by a layer of glandular tissue. This latter has a very 
remarkable structure, which is illustrated in PL XII, fig. 11. 
This figure is a general view of a transverse section of the 
whole organ, showing the vas deferens ( v . d .) just at its 
point of entrance; the external covering is composed of large 
granular cells, which are separated into groups by partitions. 
Each cell is prolonged into a fine process, which extends at 
least as far as the muscular wall ; indeed, it is difficult to 
believe that the cells do not in some way or other reach the 
lumen of the atrium, and there discharge their glandular secre- 
tion. 
There is evidently a very close resemblance between these 
groups of cells and the “prostate” of Rhynchelmis, 1 the 
prostate of that worm consists of cells with fine long prolonga- 
tions arranged in groups. 
The structure of the organ, in fact, is exactly comparable to 
that of the atrium in many Limicolse where the lining epi- 
thelium is glandular and of considerable thickness as compared 
with the surrounding muscular layer. 
The atrium of Moniligaster differs from that of Rhyn- 
chelmis in the presence of a muscular layer. Vejdovskv 
does not record the presence of a muscular layer in that worm, 
nor do his figures show any indication of it. It furthermore 
differs in the absence of cilia from the cells of the lining epi- 
thelium. In Stylaria lacustris 2 amuscular layer is present, 
and the lining epithelium does not appear to be ciliated. The 
outer covering of cells is not segregated into groups as in 
Moniligaster and Rhynchelmis; it consists of a single 
layer of large glandular cells. 
With its single vas deferens occupying only two 
segments, and opening into an atrium of the charac- 
ter just described, Moniligaster is more like certain 
Limicolse than any other Lumbricid. 
, In my former paper on Moniligaster I was unable to 
1 Vejdovsky (18), p. 332, pi. xxiv, figs. 1, 3. 
2 Vejdovsky (19), pi. iv, fig. 10. 
