and their shafts are considerably longer than in front; they dilate in a spindle-shaped
manner (in antero-posterior view, Plate XLI, fig. 16) at the end of the shaft, and then
taper to a blunt point. In lateral view (Plate XLI, fig. 17) this region is somewhat
spathulate in outline, the tip being broad, with the end of the shaft slightly bent
backward, and finely striated. More than the distal half is covered with fine spines
(pinnately arranged), which increase in length distally, and finally terminate at the dorsal
edge in a long slender whip of such fibres, one being stronger and far longer than the
others, and projecting from the midst of a basal series of large hairs (Plate XLI, fig. 17).
These bristles (G-rannenborsten of Marenzeller) appear to be capable of repair, one
presenting two fractures below the tip, yet quite stiff and useful, the callus in each case
being more coarsely striated than the normal bristle. In one small example from 358
fathoms in the Atlantic these bristles have shorter and more acutely tapered tips, and
the spines cover three-fourths of the edge, commencing just above the base. Another
and larger example from 516 fathoms (H.M.S. ‘ Triton ’) shows similar features. The
terminal whip is a true prolongation of the shaft, with lateral spines.
At the ventral edge is a group of bristles with long shafts as slender as the superior
brush-like forms, a well-marked shoulder or curve as in the anterior bristles (which
they closely resemble), and a long tapering curved finely spinous tip (subulato-serratge,
Kinberg). The spinous rows of the curved region are prominent, while the long tapering
region beyond has its spines somewhat longer just after its commencement, and thus in
antero-posterior views presents a broader feathered arrangement (Plate XLI, fig. 18).
The feet retain the fundamentally bifid condition to the posterior end, both spines
being present, though the dorsal lobe is only marked by a slight eminence (devoid of
bristles), to which the spine goes. All the bristles are greatly. elongated, but they
preserve for the most part the characters seen in front. Thus the smoothly rounded
ventral division has superiorly long slender bristles with the dilated and serrated tip.
The shafts of the strong median series are also much elongated, and the dilated tips are
densely spinous like a stiff brush, and closely akin to the condition of certain forms in
Aphrodita aculeata. . No filamentous terminal brush occurs, but the sides of the club-
shaped tip are densely bristled, and the spikes project beyond the tip. The filamentous,
tip may have been abraded in these cases, but this is uncertain.
An elaborate account of the golden yellow fibrous secretion by the spinning glands in
Polyodontes maxillosus, with numerous finely drawn figures, is given by Dr. Hugo Eisig
in his beautiful ‘ Monograph on the Capitellidse,’1 and the arrangement seems to be very
similar to that in Panthalis. Dr. Eisig considers the fibrous golden yellow secretion as •
homologous with the spines and bristles of these and other Annelids, and enters into a
lengthened description of the structure of similar glandular secretions in both Vertebrates
and Invertebrates. The glands are long tubular structures which pour their secretion
externally by an aperture in the dorsal papilla above the foot. The threads thus
secreted are mingled with mud in the formation of the tube, and Mr. Arnold Watson has
described the mode by which the animal ruptures the anterior end, and, throwing it
outward, adds layer upon layer in this manner, so as to constitute a massive tube.
Naples, 1887.
Pruvot and Racovitza’s view that the spinning glands are the homologues of the
dorsal setigerous glands, forming the material for the tube instead of the dorsal bristles,
is not free from doubt.
Reproduction.—In a large example procured in July, 1868, in Shetland (78 fathoms),
a series of large ova occurred in the perivisceral chamber. The embryo must therefore
attain considerable size before extrusion.
Habits.—Like others of the group, Panthalis CErstedi inhabits a tube of mud, about
3£ inches long and about l£ inches in diameter, with loose extensions of mucus at either
end, thus concealing the entrances, and for an example of which I am indebted to Prof.
Herdman. The estimated internal diameter of the tube is usually about f inch, while the
thickness of the walls in the centre is about £ inch. The tube is composed of a number
of layers of the thread-like secretion interspersed with mud, these layers not being
parallel, but curving outwards, since, according to Mr. Arnold Watson, from whose
interesting account1 of the habits of the species the foregoing is taken, rupture of the
anterior end frequently takes place.
The animal crawls along the surface of the ground, can reverse itself in its tube,
and can also swim a little' in the water.
The American Euarche tubifex described by Ehlers3 makes a curiously ringed
arrangement of the anterior end of the tube, probably due to the gradual narrowing of
the calibre of the tube at this end.
Kinberg in 1857 described the species thus :—The .cephalic lobe with the peduncles
equal to a fifth part of the length of the palpi, tentacular cirri longer than the tentacle;
bristles of three kinds, subulate, serrulate, bipennato-penicillate, bearded. No foot papillaa.
Marenzeller published an excellent account, with good figures, of the bristles, as
well as pointed out the functions of the spinning-glands in regard to tube-making.
Pruvot and Racovitza give two new species of this genus from Banyuls with accurate
. and beautiful figures, viz. P. Lacazii and P. Marenzelleri. After a careful study of the
first-mentioned as given in the authors’ descriptions and figures, I have doubts as to the
need for specific distinction from the British form, though there are a few minor variations,
such as the increased size of the so-called branchial papillas in front. I t would
also appear to be a question whether the French authors have not placed too much
weight on the mere curvature of the ventral bristles of their Panthalis Marenzelleri,8
especially as Kinberg’s artist may have had a mounted preparation for illustration, and
thus the curves would disappear. The twist or double curvature referred to is present in
all the examples of Panthalis (JErstedi that have come under my observation, and the
bristles of the first" pair of feet (bearing the tentacular cirri) are likewise present. The
comparative length of the tentacle is not always to be relied on, though in young
specimens the tentacle seems to be about the same length. The same remarks apply to
the median papilla of the proboscis. The absence of the ceratophore is remarkable.
The bristles in young forms show the finer characters better than in the adults—in which
1 Ibid., pp. 170, 183, &c.
2 ‘Annelida of the “ Blake,” ’ &c., p. 54, Taf. 12, 13.
3 “ Faune des Annel. de Banyuls,” ‘Arch. Zool. exper.,’ 1895, p. 451.