Proboscis (Plate XXXIV, figs. 3 and 4) exsertile, cylindrical, furnished with j§
papillae, the median—upper and lower—longer, especially the superior. In the British
forms it projects from the mouth like a tentacle, and tapers from base to apex. The
inferior, also conical, is much less, and has an inwardly projecting hood or arch at its
base. The four maxillae are elongate, brownish, strongly hooked at the tip, which is
a process of the dorsal rib, and with an attached flat blade, the inner edge of which has
six teeth (I£inberg says six to eight teeth, while Marenzeller shows in his figure traces
of six).
No pregastric caeca occur, and in this respect i t agrees with the Sigalionidae. The
stomach is very muscular. The lateral intestinal caeca are large and elliptical, with a
narrow neck. .
Scales (Plate XXXIV, fig. 5) thirty-nine pairs (Kinberg), in life pearly white,
semi-transparent, the first three pairs flattened, covering the dorsum, the rest cam-
panulate, and about one-third the breadth of the dorsum on either side, the centre being
bare. “ During life these do not rest upon the body, but in front are tilted up, so as to
meet at an angle above the prostomium, the last few pairs of elytra also assuming a
similar position. . . . A constant rising and falling of the elytra, as though to
facilitate the passage of water for the purpose of respiration, was observable ”
(Arnold Watson). They are perfectly smooth, of fair thickness, and richly supplied
with nerve-trunks, as in the Polynoidse. Mr. Watson found in a living example that
posteriorly the last two pairs only met in the middle line, whereas in a specimen
in the British Museum, dredged by Sir John Murray in 44 fathoms, the last six pairs
did so. -
Feet.—The dorsal division of the first foot bears two long and rather slender spines,
and several long slender bristles, finely spinous from a short distance above the base to
their capillary extremities. The slenderness of these hairs is in contrast with the condition
of the homologous organs in the Polynoidse. The spines, are minute.
The second foot is somewhat complex, and is specially interesting in connection with
the action of the parts in the formation of the tube, as recently described by Mr. Arnold
Watson. The foot is essentially bilobed,—that is, divided primarily into a dorsal and a
ventral division, the latter, it is true, being again subdivided. The dorsal division has
its spine, and forms an even ridge dorsally—terminating in a projecting globular or clavate
knob—directed downwards and projecting as far as the ventral division. Beneath are a
series of stiff bristles of the type seen in the foregoing process, but much stronger. They
taper from the base to the slender apex, and the short but distinct spines begin a little
above the former. The main ventral division is trilobed. The uppermost bristles
spring rather above the lobe, point upwards and outwards, and have stout shafts ending
in a spinous region dilated at the base and tapering to a slender tip. As we proceed
downwards the spinous region becomes more slender and tapering—the enlargement at
the base of the region gradually diminishing, and the shafts also becoming more slender.
An accessory lobe (bract) occurs at the ventral border, and in it the bristles, though
retaining the same type, become more slender, and the tapering spinous region shorter.
The ventral cirrus of this foot agrees with the homologous organ in the Polynoidse, and
is apparently used in the same manner. Though certain modifications exist in this foot,
yet the general structure is. so much in accordance with the type in others that the
functions in all probability are not very diverse.
The third foot presents a short subulate dorsal cirrus and a somewhat clavate dorsal
lobe, with finely serrated slender bristles. The ventral is a massive but short lobe, having
superiorly a small group of bristles of the type of those in the foregoing foot, the spinous
regions being slightly bent backward and downward, with prominent rows of spines at
the commencement. Beneath are about six short and strong bristles with spear-shaped
tips, slightly curved and quite smooth,—in short, the extremities of the typical series
without the spines, but with the accessory process at the tip. These cover the main or
central region of the foot, with intervals between. From the accessory process at
the ventral edge of the foregoing lobe springs a group of more slender bristles of the
type of the superior series, with well-marked alternate spines. In ordinary views (in
spirit) the serrated concavity of these bristles is directed upward. As Pruvot and
Racovitza observe, .one or two simple serrated bristles occur at the inferior border of this
foot. They probably indicate the original condition of the series. The subulate ventral
cirrus extends beyond the fleshy part of the foot.
The fourth foot has the short slender dorsal bristles under the lobe superiorly. In
the ventral division the bristles preserve the same type superiorly, but they have spread
a little downward. The tips of the great spines beneath are somewhat longer, and the
upper has a slender terminal whip. In like manner the slender inferior bristles have
spread upward beyond the two lower strong bristles, their structure, however, showing
no marked difference from those of the previous foot. The accessory ventral lobe is a
mere notch.
The fifth foot exhibits no noteworthy change except the increased distinctness of the
dorsal lobe, and the same may be said of the sixth.
The seventh foot agrees with the foregoing, and shows very well the series of
globular warts or papillge along the dorsal ridge above the cirrus. There are about eight
of the stout median bristles with the enlarged tips and terminal brush.
The eighth foot inaugurates a change, for, superiorly, the slender bristles with the
brush-like tips have appeared in the ventral lobe, while the dorsal division is only
indicated by an elevation without bristles. There are about five of the strong median
bristles with the filiform brush, while the inferior group of slender forms with the curved
spinous tips remain as before. The glandular apparatus for the peculiar secretion
commences in this foot.
The foot and bristles gradually assume the typical condition (Plate XXX, fig. 8),
but the foot varies little from the foregoing, presenting a smaller superior and a larger
inferior spine projecting in the centre of the median lobe, a rounded process superiorly,
then the more prominent median lobe, and an inferior process. The brush-shaped bristles
superiorly have very long slender shafts, which slightly dilate distally, then taper and
terminate in a point. From the sides of the tapering part a series of long hair-like
spines project like a brush (bipennato-penicillatae, Kinberg), the enlarged region at the
base having a shorter series (Plate XLI, fig. 15). The hair-like bristles either form a
hair-pencil, as in the figure, or a broader brush at the tip. These bristles occupy about
the upper third of the median lobe. Eight or nine strong aristate bristles then follow,