174 MR. CYRIL CROSSLAND ON THE [ Feb. 17, 
staining nerve-nuclei of the brain (which are similar to those 
seen on the outer side of the ventral nerve-cords &ec.) is shown 
distinctly, this replacement being complete in fig. 10, where the 
epidermis is composed entirely of nerve-cells. 
The eye-spots are a pair of groups of cells, each containing 
numerous minute granules of black-brown pigment. These are in 
continuity with the nerve-cells of the brain, but are anterior and 
dorsal to its fibrous part. 
The celom is small and broken up into several distinct portions. 
The largest of these are a pair of spaces lying laterally and 
ventrally to the gut (fig. 12), bounded dorsally by the powerful 
muscles of the seta-sac. Dorsally and medianly, commencing as a 
space in the prostomium, is a third part which posteriorly becomes 
a mere canal surrounding the dorsal blood-vessel. In the region B 
the eelom is more normal, though reduced in size. It remains 
divided into right and left halves by the dorsal and ventral 
mesenteries of the gut. 
The vascular system consists of dorsal and ventral vessels, both 
running in the gut-mesenteries. The former breaks up at the 
base of the prostomium into three branches (fig. 10), and large 
connecting-vessels are found in the anterior segments. Posteriorly 
the dorsal vessel forms a large sinus covering the dorsal wall of 
the gut (fig. 13). 
Alimentary canal.—The mouth is richly ciliated, and the outer 
ends of its columnar epithelial cells contain a few minute specks 
of the black-green pigment so characteristic of the family. These 
are absent from the narrow triangular gut of the region A, but 
reappear in great quantities in the larger thick-walled alimentary 
canal of the regions B and C (fig. 13). 
The gut-lining here consists of long crowded cells, the swollen 
distal ends of which are crowded with minute specks of the 
pigment, indicated by dark dots in the figures. 
The transverse sections of the notopodial gills, shown in fig. 13, 
are interesting. The space which they contain is ccelomic, and at 
its centre is a bundle of five or six setee wrapped closely together 
by fleshy tissue. The transverse section of this resembles that of 
a telegraph-cable, the wires being represented by the sete. At 
each end of the oval section is seen a sharply-cut groove, the 
sides of which are of granular, rather deeply-staining protoplasm, 
without nuclei, supporting externally very long cilia. Laterally 
is a more deeply-stained area of the epithelium, perhaps of nervous 
function. 
PHYLLOCHAHTOPTERUS PICTUS, sp. n. (Plate XVI. fig. 5.) 
The tubes of this species are brown and translucent, quite free 
from sand or mud. They were found clustered together in con- 
siderable numbers on the under side of a large stone at low-water 
level on Pungutiayu islet, Wasin. Each tube has two openings, 
each limb of the U being about 4°5 cm. long. The bending is 
irregular, and they are twisted and fused together, so that 1t 1s 
usually almost impossible to separate out any one tube. 
