No. 2.] A NEW MARINE TRICLAD. E77 
5. Lxcretory System. 
In hardened specimens and in sections I have looked for the 
water-vascular system in vain, but in the living animal more 
or less extensive portions of it were readily detected when just 
the right amount of compression was applied. It consists of 
a rather stout and somewhat zigzag main trunk on either side 
of the body (Fig. 4 ¢ex), running just lateral to or immediately 
over the tips of the gut-diverticula. The trunks arise near the 
anterior end of the body and fade away in the caudal region. 
Into the main trunks open at very irregular intervals, and 
often by twos and threes, jagged and ramified branches. No 
flame-cells were seen in the main trunks, but at intervals 
in slight dilatations of the larger branches (Fig. 11 wf) the 
play of the flagella could be watched for minutes at a time. 
The movements of the flagella are very rapid, and resemble 
an endless chain moving behind a slit-shaped opening in 
a direction parallel to the long axis of the slit. I have not 
seen the funnels figured by Lang and Chichkoff. The two 
main trunks are connected with each other at the posterior 
end of the body by means of anastomosing smaller branches. 
A similar connection at the anterior end could not be made out. 
I do not lay much stress on this negative observation, since 
Iijima figures an anterior connection between the main trunks 
in the young Dendrocelum lactewm (Pl. XX, Fig. 2), although 
he seems not to have found a posterior connection. Chichkoff 
also gives an excellent figure of the anterior anatomoses in 
the same species (Pl. VIII, Fig. 38). 
The pharyngeal excretory system so beautifully figured by 
Chichkoff (Pl. VIII, Fig. 41) was not seen in Syncelidium. 
Nor have I seen anything which might be interpreted as an 
opening of the water vascular system to the exterior, either 
on the dorsal surface (dorsal pores of Iijima) or in the 
pharynx, where the occurrence of an opening is suspected 
by Chichkoff. 
