Gatty Marine Laboratory, St. Andrews. 229 
prominent, and their resplendent tufts of bristles make them 
still further conspicuous. ‘The dorsal lobe presents just 
behind the ridge of the foot the basal segment of the dorsal 
crus, while the setigerous region in front is acutely conical, 
the long black spine passing to the apex. Hach bears a tuft 
of simple and somewhat stiff bristles, which taper gently to a 
hair-like tip. The whole bristle is marked by transverse stria 
or camerated till within a short distance of the tip. More- 
over, the tip is furnished with a regular series of minute 
spikes. The latter are much more conspicuously developed 
in T. Claparédit from Naples, the spikes in some being 
continued far downward, and forming a feature along each 
side of the bristle. It was the comparison between the dorsal 
bristles of the two forms that many years ago led to their 
separation. Claparéde had overlooked the presence of these 
spikes in his species, as also has Roule in the present form. 
The ventral division is irregularly conical, with a prominent 
papilla for the powerful black spine or two. ‘he upper slope 
of the region is downward and outward, the inferior (more 
abrupt) is downward and inward. In shape the foot thus 
differs from that of 7’. Claparédit from Naples, which is longer, 
and the inferior setigerous region has an abrupt truncated 
extremity with, superiorly, a papilla for the spine. The base 
of the dorsal cirrus is carried erect in the specimens from the 
‘ Porcupine,’ whereas it is horizontal in 7. Claparédi’, but 
this is not of much moment. ‘The bristles (Pl. I. tig. 6) form 
a dense tuft. The shaft has a close series of longitudinal and 
transverse striz, is slightly dilated at the distal end, and then 
bevelled—from the attachment of the terminal process to the 
point. The distal blades are longest towards the upper third 
of the tuft, shorter dorsally, and sho:test ventrally. Hach is 
flattened, slightly tapered, and curved distally, where it is 
bifid, with a secondary process beneath. Oblique striz slope 
from the serrated edge of the blade downward and backward. 
The bevelled base of the blade is attached by a web to the 
shaft. These bristles, though pale, are finely iridescent, and 
in some are brownish in the posterior region of the body. 
In comparing these bristles with those of 7. Claparédii 
from Naples the whole bristle is more slender, the tips longer 
and more delicate, and the bifid forked tip more minute (PI. I. 
figs. 7 & 8). The boldly bifid nature of the tip in 
T. Claparédi (fig. 7) and the more distinct secondary process 
are in contrast with fig. 8 (7. atlantica) , the second or interior 
spur being curved and the secondary process adpressed. 
The serrations on the edge of the blade are similar. ‘The 
backward tilt of the tip of the bristle is seen in both, but 
Ann. & Mag. N. Hist. Ser. 7. Vol. vin. 17 
