46 A. CG. OUDEMANS. 
other lacunar spaces, especially in the foremost half of the 
esophageal region, by transverse fibres, and only now and then 
communicate with the other lacune. At first in the hindmost 
half the separation is less distinct, they lose their vascular 
character and unite more with the other lacune. They always 
remain within the longitudinal muscular layer. 
About the region where the median vessel leaves the probos- 
cidian sheath, two ventral lacunze become larger than the rest, 
aud are always visible at the same point. A hundred slices 
further on there are some small lacunar spaces, but after- 
wards no more. These two lacune are the foremost portions 
of the ventral vessels. In the meanwhile the two proboscidian- 
sheath-lacune have disappeared, and the remaining lacune 
arrange themselves so that they bear a likeness to the rudi- 
ments of transverse vessels, so that I cannot precisely note 
where the foremost well-defined transverse vessel may be said 
to occur. When the first well-defined vessel is visible the two 
proboscidian sheath lacunz have already disappeared. The rest 
is entirely similar to Valencinia and Polia. 
The inner coating of the blood-spaces with the epithelium 
and the thin hyaline basal layer was everywhere the same. In 
none of the three specimens examined did the median vessel 
beneath the proboscidian sheath lie against the intestine or 
against the proboscidian sheath, but freely amidst the gelati- 
nous stroma. Outside the hyaline basal layer, nuclei were 
grouped. The same is the case with the ventral vessels. 
From what I have seen further on in the intestinal region, I 
may state that they have only a thin layer of circular and a — 
thick one of longitudinal fibres. 
The dorsal vessel in the proboscidian sheath displays the 
same peculiarities which I mentioned in speaking of Valen- 
cinia and Polia. 
The transverse vessels, as in Valencinia, were so closely 
attached to the wall of the intestinal diverticula that they 
appeared to have a common wall. 
The situation of the nephridial system is the same as in 
Valencinia and Polia. To the left and to the right it lies 
