292 CHONE FAUVELI. 
a more prominent ventral papilla. The deep dorsal] fissure is contmued to the second 
segment, where it is dilated, and from this the mid-dorsal groove passes backward to the 
anterior border of the eighth segment, then it inclines to the right—cutting off in its course 
ventralward a narrow portion of the ninth, and, reaching the mid-ventral line in this 
segment, thereafter proceeding to the tip of the tail, the last part of its course being 
generally more deeply grooved in the preparations. The body of the fresh specimen is pale 
pinkish, and in the newly preserved form is of a pale skin-colour. 
The branchiz vary from twelve to thirty-six on each side, and are connected together 
almost to the tip by a membrane—the dorsal fissure, however, causing a gap in the funnel. 
In preserved examples the filaments are often slightly spiral, and the tips are incurved. The 
filament is stiffened by a chordoid camerated axis as in Sabella, and it is not less in diameter. 
The tip of each process is characteristically formed—with a broad wing at the base and 
tapering to a fine point. A slender axis, apparently from the chordoid skeleton, passes 
along the centre of the flattened tip almost to its extremity. The pinne are long even 
to the base of the flattened terminal process, and have a central (chordoid) axis, the tip being 
smoothly rounded or occasionally slightly enlarged. The pinne at the bases of the filaments 
—that is, near the mouth—are elongated, the last one or two being so long as to resemble 
cirri. In the centre are two or three folded lobes apparently in connection with the oral 
aperture, and near the dorsal fissure is an oblique fold of some length, the distal end of 
which is split into filaments. The two tentacles proper are on the inner border of each 
ventral fold, and they terminate in a tapering filament. When a suitable example is 
observed, the slender cirri arise at each side of the mouth and are quite free from the 
branchie. Six or more occur on each side as delicate filaments little tapered distally. The 
mechanism of the entire elaborate apparatus is complex. The length and degree to which 
the tip is webbed vary considerably, and in the Arctic form it is more elongate. 
The cutis is smooth, has a finely iridescent or nacreous lustre, and when removed has 
a bluish aspect. In intimate structure it is crossed by fine lines, which give it a fibrous 
appearance, but at the segment-junctions white bands occur, and these are tesselated. A 
series of powerful circular fibres occurs beneath the skin and its basement-tissue, whilst the 
longitudinal bands conform to the type of the family. 
The collar runs smoothly into the first segment, which is of considerable antero-posterior 
diameter and uniformly rounded. It has on each side, a little in front of the segment- 
junction, a small tuft of bristles and a pale spine. ‘The bristles are simple winged 
forms, with tapering tips, the edges of the wings being serrated. They slant dorsally and 
forward. Some of these long anterior bristles present a peculiar twist below the wings, but 
whether this is artificial or otherwise is unknown. The succeeding seven pairs (which issue 
~ just in front of the median ring) have modified tufts, consisting of a dorsal series of bristles 
with tapering tips like those of the first series, with serrated edges, and a ventral series of 
spatulate bristles (Plate CXXX, fig. 2 and sections), the slope of both being obliquely upward 
and forward. The spatulate bristle is smallest at the base and gradually enlarges into a 
finely striated shaft, which remains cylindrical until the wings appear, and then tapers to 
a blunt point. The wings rapidly widen on each side and soon end in a blunt tip. Moreover, 
the tip often presents a slight marginal fold. The anterior tufts of simple bristles (at and 
after the ninth) are characteristic when contrasted with the northern Chone infundibuliformis 
