SEA-FISHERIES LABORATORY. 161 
ON THE TUBE OF A RARE POLYCHAETE WORM, 
TEREBELLA (LANICE) SETICORNIS, McIntosu, 
DREDGED WEST OF THE ISLE OF MAN. 
By ARNOLD T. WATSON, F.L.S. 
[Read 12th May, 1916.] 
The specimen to which this note refers was collected by 
me about 20 years ago, when dredging with Professor Herdman 
and the members of the Liverpool Marine Biology Committee, 
to the west of the Isle of Man, 20 to 30 fathoms. 
The tube only was secured, of which a full-sized drawing 
is now given (see fig. on next page). 
This tube, the bore of which is 38; in. (say 4 mm.) and the 
length over all 3? in., is formed of fragments of shell and flat 
stones. These fragments in the lower part are fairly large, 
but for a short distance, just beneath the two triangular plates, 
or palms, which support the radiating filaments forming the 
fans, the fragments are much smaller and the external diameter 
of the tube is consequently reduced. 
The triangular palms, although each consisting of about 25 
fragments of shell or stone firmly cemented together, are 
beautifully symmetrical in outline. They are extensions of 
opposite edges of the mouth of the tube, which are expanded 
and so flattened out as almost to touch one another. 
To the edges of each palm are attached about 14 radiating 
filaments. These filaments, practically all of which are un- 
branched, are composed of sand-grains, echinus spines, and 
miscellaneous material, attached end to end, in single line, 
supported by the mucous secretion of the worm. 
Several of the filaments are incomplete or broken, but 12 
are terminated by hair-like processes, consisting of smooth 
