420 EKUPHROSYNID. 
from the Copenhagen Museum. The annelid has branchie with long, taperig terminal 
processes, a rounded, calcareous operculum and three pairs of thoracic bristles. The collar- 
bristles have a basal web, with moderately distinct serrations, and a tapering blade with 
minute serrations. These bristles thus approach those of Spirorbis granulatus and S. borealis. 
The third series appeared to have sickle-shaped bristles. The tube has three sharp ridges 
and two grooves, the ridges only differing from those of S. granulatus in their thin, spinous 
edges, and the median one in some becomes deeper at the aperture so that it forms 
conspicuous keel, with a small sharp point over the circular aperture. 
ADDITIONS TO THE BRITISH MARINE POLYCHAITA SINCE THE 
PUBLICATION OF THE MONOGRAPH. 
Famity HUPHROSYNIDZ. 
Post-Larval Huphrosyne. 
Procured by Mr. Chadwick in a tow-net in Port Erin Bay, December, 1905. 
Anteriorly in the microscopic preparation the head consists of a somewhat shield-shaped 
lobe, broad and slightly dimpled in front, narrower behind, and with a more deeply stained 
clavate band along each side—at the anterior end of which is a minute dark eye. This 
shield-shaped region is minutely streaked and dotted, apparently from the minute cells and 
eranules taking in the stain. On each side of this area is a tentacle, the base of which is 
enlarged and the tip filiform and tapering. 
The entire body has a more or less circular outline, and the four pairs of feet radiate 
outward characteristically, the anterior pair being wide apart, and directed almost straight 
outward, or with a slight obliquity forward, whilst the last pair is somewhat smaller, and 
more nearly in a transverse line. Hach foot consists of a setigerous process tapered toward 
the tip, so that it resembles a long cone with a tuft of translucent, slightly curved, simple 
bristles issuing from it in a fan-like manner. Each bristle has a translucent straight shaft, 
the curved region at the tip being finely spinous on its convex side. Amongst these is a 
shorter, stouter form, also curved at the tip, but smooth. Shorter and more slender bristles 
apparently represent the dorsal series, and, in all, these form a group at the tentacle, their 
tips, which are finely serrated, curving inward at the side of the head. A similar tuft occurs 
on the dorsum of each foot, though in the smallest (youngest) they are not visible on the 
two posterior feet. The curvature of these bristles may be partly due to preservation. The 
alimentary canal seems to go straight backward to the vent, the last portion, occupying 
a little less than a third of the length of the body, bemg more deeply stained. A median 
fissure separates two minute and somewhat ovoid lobes between the bases of the posterior 
feet. 
So far as can be observed, this would seem to be the pelagic young of Huphrosyne, prob- 
ably of H. foliosa, the common species of the more southern waters. The general outline, 
