Gatty Marine Laboratory, St. Andrews. 171 
body. Each consists of a tapered filament with a somewhat 
camerated axis, giving a transversely barred aspect due to 
what De St. Joseph calls mucous cells, which have not the 
differentiation of the Sabellid axis, and become indistinct in 
mounted preparations. The long diameter of these cells is 
about 2500th of an inch, less in their short diameter. A 
double row of proportionally thick pinne is attached to the 
inner edge, each pinna having a central axis of similar 
structure to that of the filament, and the tip is bluntly 
rounded and often curved. The distal pinnz diminish in 
length, the last being a mere papilla, and the filament ends 
in a short smooth process, often slightly clavate in spirit 
and more opaque than the rest. Moreover, the dorsal fila- 
ment on each side ends in a thin, flattened, and somewhat 
ovoid plate, the pair performing the function of an oper- 
culum. In fresh examples the pinne present a double row 
of rough granular cells (mucous cells, De St. Joseph) 
set in a hyaline matrix, and in some views these have a 
spiral arrangement. 
In an example a pair of elongated glandular sacs (ne- 
phridia ?) occurred in front of the sixth bristle-tuft of the 
anterior region im the ccelom, the tips crossing each other. 
In structure they were granular. The intestinal canal is 
dilated behind the anterior region (seventh bristle-tuft), and 
runs as a straight tube from end to end. No diatoms or 
radiolarians were found in it, only brownish granules and 
sand-particles. The colour is translucent orange with the 
intestine dusky brown. It tints the tube, so that it has a 
faint reddish hue when the animal is within. The branchiz 
are pale. 
The first region of the body has seven or eight pairs of 
bristle-tufts, which, with the peyistomial segment, makes a 
total of eight, the second region has from thirty-five to forty 
segments. The body is somewhat flattened both dorsally 
and ventrally, with a median groove in the posterior region 
on both surfaces, and terminates posteriorly in an anus 
with a prominent papilla at each side, which, according 
to De St. Joseph, may assist in the formation of the 
tube. The anterior region has the alar membrane, which 
stretches from the collar along each side to the posterior 
edge of the last segment of the anterior region, where it 
bends ventrally and joins that of the opposite side, as in 
Protula, leaving a free flap posteriorly. It forms a more 
uniform margin than in Protu/a, and is, in the preparations, 
generally directed obliquely upward, the bristle-tufts being 
