208 
The Irish Naturalist. 
October, 
that organ : it here, without making any connection with 
the him en of the atrium, turns sharply round and, still 
hidden in the wall, runs right up to the. apex of X. Here 
it again turns and opens into the lumen of X. Following 
down this latter, it is clear that the lumen of X opens freely 
into the lumen of the atrium. The band, which was 
interpreted by Bowell as a continuation of the vas deferens to 
Y appears in the sections as a thickening of the wall of the 
atrium ; it has no lumen, and forms no definite connection 
with Y. , A transverse section through the organs 
approximately along the line M in figure i is shown in 
Plate I. The free oviduct (ov.) and the descending 
free part of the vas deferens (v.d.d.) appear as separate 
Fig. 4. — Diagram of the course of the vas deferens. 
organs : in the organ X there are two lumina lined with 
epithelium, one (pen.) the main cavity, continuous below 
with the cavity of the atrium, the other (v.d.a.) much 
smaller, is the ascending part of the vas deferens which 
connects v.d.d. to pen. 
My results therefore agree with those of Simroth-Taylor 
in so far that I regard X, and not Y, as the penis :^ but the 
vas deferens opens into the extreme apex of this penis and 
not laterally. In this way the arrangement in the Irish 
species becomes more like that found in V . pellucida, in 
which the vas deferens is closely bound down to the penis 
though not actually incorporated in its wall. The organs 
