CIRCULATORY APPARATUS OF THE NEMERTEA. 57 
fig. 64a portion of a transverse vessel, drawn with different 
focussing of a microscope. 
13. Amphiporus pulcher (Johnst.), McInt., figs. 6, 7, 9, 38. 
Of this type of Hoplonemertea I cannot give any sum- 
mary, not having been able to examine all the details. By 
analogy we may, however, conclude that it is essentially the 
same as of Amph. Jactifloreus (Johnst.), McInt., which 
will be treated subsequently. 
In a head of a specimen of this species which I was able to 
examine, I saw very distinctly that there was only one single 
aperture to both the proboscidian sheath and the mouth (see 
also Hubrecht 35); the upper curve of the aperture is that 
of the proboscidian sheath, and the lower one that of the 
mouth. How the cephalic vascular loop (for here are no 
lacune but two vessels, which communicate anteriorly, figs. 
6,7,9) is situated in relation to the proboscidian sheath I have 
not seen. In some slices I believe I saw the two vessels ; they 
lay laterally (see fig. 38) and within the longitudinal muscular 
layer. In this area also the whole nervous system is situated. 
I have not observed whether the two vessels go through the 
cerebral ring, nor how the dorsal vessel communicates with it. 
But I could very well see that the dorsal vessel lies in the 
proboscidian sheath, but only for some twenty sections ; it then 
leaves it. A little behind the brain I first saw very distinctly 
the two lateral vessels. They lie through the whole length of 
the body, beneath the level of the nerve-stems. 
In two portions of the intestinal region [ did not see trans- 
verse vessels. In a tail-piece I found them lying above each 
diverticulum. The mutual communication of the three longi- 
tudinal vessels is the same as in the Schizonemertea, 
above the intestine and before the anal commissure of the 
lateral nerves. 
Of the nephridial system I may mention that Prof. 
Hubrecht has found in one specimen that the excretory ducts of 
the system lie just behind the ganglia. He had noted it down 
on the preparation. These ducts are very easily to be seen, 
