Gatty Marine Laboratory, St. Andrews. 139 
setigerous region, which appears to have a small papilla 
above it. 
Whilst the dorsal cirrus, as mentioned, continues for some 
distance of considerable length and thickness, the ventral in 
the 2nd foot has diminished to a short conical process with 
a thickened base, and it is still further reduced posteriorly. 
At the 10th foot (Pl. XI. fig. 15) the dorsal cirrus forms 
a long subulate organ, supported by several (three) pale 
slender spines which enter its base. At this region also 
ventrally is a slight prominence, which indicates the papilla 
developed in the subsequent feet. Two powerful brown 
spines, the tips of which project through the tissues, occur 
in the setigerous region, which in lateral view presents an 
oblique edge, sloping from above downward and inward—a 
feature largely due to the development of the posterior lobe 
or flap. Superiorly is a small clavate papilla which is 
directed forward and outward. It carries dorsally a series 
of rather stout, long, winged bristles of a pale brownish or 
dull yellow hue (Pl. XI. fig. 16). A slight bend occurs 
below the tip, which is comparatively short and abruptly 
tapered. They extend rather beyond the tip of the dorsal 
cirrus in the preparation. At their bases are a few brush- 
shaped forms (Pl. XI. fig. 17). The ventral bristles are 
paler (translucent and faintly yeilowish), have a short thick 
shaft with a very slight bend, a faint articulation, and a 
long slightly tapered distal piece (Pl. XI. fig. 18). So 
far as observed this condition is characteristic of Morphysa, 
but is rare in Lunice. The ventral cirrus forms a short 
conical process at the tip of the large glandular ventral 
enlargement. 
The 20th foot agrees with the foregoing, except that the 
papilla at the ventral base of the dorsal cirrus is larger, 
Two spines support the organ. ‘The setigerous region has 
three black spines. The tips of both dorsal and ventral 
bristles are somewhat shorter. The edges of the terminal 
pieces of the ventral bristles are finely spinulose. 
The outline of the 30th foot (Pl. XI. fig. 19) consider- 
ably differs. Branchiz have now appeared. ‘The dorsal 
cirrus is more slender, and opposite the papilla at its base 
ventrally a short branchial process projects dorsally, with a 
conspicuous afferent and efferent vessel. The setigerous 
region is now acutely conical, with a smaller rounded flap 
posteriorly. The tips of three strong dark brown spines 
project at the upper part. The dorsal bristles are more 
slender and longer, and with a slight bend below the 
