Gatty Marine Laboratory, St. Andrews. 221 
curve. The usual series of bifid papille occur on the distal 
margin (in extrusion). 
The body has the typical shape. The posterior region is 
absent. The bristles resemble those of LV. longisetosa in 
their curvature and strength, but the two annelids are readily 
discriminated by the reduction of the dorsal lamella in the 
Japanese form. 
In the typical foot the dorsal lamella has a stiff conical 
outline (Pl. I. fig. 1), standing nearly erect instead of having 
the backward slope of that in N. longisetosa, and it is directed 
outward and slightly upward. The dorsal cirrus is a slender 
subulate process with an enlarged base, and is connate with 
the base of the branchia. The latter is somewhat slender, 
and is curved inwards, as in N. longisetosa. The capillary 
dorsal bristles are pale, strong, and curved backward from 
a limited origin below and in front of the lamella. The spine 
is indistinct, but pierces a papilla between these bristles and 
the camerated anterior series. The line of origin of both sets 
of bristles is unusually limited. Unfortunately the bristles 
have lost their finer characters, but both the capillary and 
the camerated are stout, the segments in the latter being in 
many narrow. 
The inferior division presents dorsally a curved, slightly 
tapered, branchial process, somewhat thicker than the dorsal 
cirrus. The tip of the lobe is bluntly conical and bevelled 
from above downward in lateral view—from the shape of the 
posterior lamella. The capillary and barred (camerated) 
bristles lie in front, the latter having no perceptible guard or 
fillet to their base anteriorly. The ventral cirrus is pro- 
portionally large, with a swollen base and tapering extremity. 
In describing Nephthys dibranchis in the Annelids of the 
* Challenger,’ allusion was made to the species thus :— 
“A similar species (Nephthys Jeffreysii) comes from Japan, 
lat. 38° 58’ N., long. 130° 27’ E., where it was dredged by 
Capt. St. John. The structure of the foot, however, shows a 
characteristic divergence. Instead of being rounded, the 
superior lamella has a nearly straight upper edge, the tip is 
pointed, and the external border convex. ‘The superior lobe 
of the foot is less produced than in the foregoing, the cirrus 
at the base of the branchia is symmetrically dilated at the 
base, and thereafter forms a nearly cylindrical process. The 
branchial process is both shorter and more slender, and 
the enlargement a little beyond the base externally very 
prominent. ‘The inferior lobe is very short, presenting 
superiorly a short, straight, branchial process which extends 
a little beyond the tip of the lamella beneath, which is some- 
