hook being present. All are very translucent and delicate. One of the elongated forms
near the dorsal edge of the fascicle is shown in Plate XXXIX, fig. 25, and a more highly
magnified; tip in Fig. 27, the arrangement of the spines and the short bifid tip being
characteristic. The bristles from the middle of the foot are exceedingly translucent and
very faintly serrated (Plate XXXIX, fig. 26, and a tip more highly magnified in Plate
XXXIX, fig. 28). In large examples from Norway the dorsal bristles show more
acutely-tapered tips, but otherwise the characters closely approximate.
The dorsal cirri have a filiform tip without enlargement, and rather long clavate
papillae sparsely distributed. The ventral cirrus is slender and elongate with a finely
tapered tip, which in the preparations ends in a slight enlargement. Short clavate
papillae—sparsely distributed—occur on the surface. The tip reaches considerably
beyond the base of the lowest bristles.
The species is broadly distinguished from E. impar by the deep brownish hue of the
dorsum and the brownish-purple proboscis, by the structure of the scales, which have
only large horny papillae and few and slender cilia, by the longer, more delicate, and less
tapered dorsal bristles with shorter tips, and by the more slender ventral bristles with
much more finely tapered tips. '
The capture of a variety during the * Porcupine5 Expedition of 1870 at 690 fathoms,
in which the eyes are large—especially the anterior pair, which have a lens-like corneal
thickening—and still more the presence in Norwegian waters of a form closely resembling
Evarne Johnstoni in colour, but differing in having very large eyes and in other minute
particulars, raise the question as to how far such species vary with age, sexual conditions,
and environment. The younger Norwegian forms agree with the description of
E. Johnstoni, except that some have larger eyes (without a lens-like thickening). In the
larger and older forms, however, the eyes still further increase in size, the lens-like corneal
thickening of the anterior pair leaving only a rim of black pigment round the edge. The
posterior pair are also provided with the central lens-like thickening. The dorsal bristles
are broader, more acutely pointed, as well as somewhat more closely spinous; and the
smooth portion at the tip is longer, so that it is dagger-shaped. In the ventral bristles
the tips are bifid even to th e , ventral edge of the foot. Age, therefore, considerably
alters the foregoing organs. The scales differ from those of E. impar, and agree with
those of E. Johnstoni.
The prominent question therefore is, can Evarne impar pass insensibly—by epigamy,.
for instance—into E. Johnstoni, as in many other groups of annelids ? So far as present
observations go, a negative reply would seem to be most in harmony with the structure
of the scales, the eyes, bristles, and the geographical range. Further knowledge may
show the propriety of union, but at present it is better to: leave the question as it is.
Prof. Giard (1886) finds a third and closely allied species of Evarne commensalistic
on Cucumaria pentactes off Brittany and the neighbouring shores of France. 3
3. Evarne H ubrechti,1 McIntosh, n. s.
Specific Characters.—Head comparatively small, and in the adult the eyes are very
large; both pairs more or less lateral in position. Median tentacle long, tapering,
1 Named after the distinguished Professor of Zoology at Utrecht.
smooth, and the tentacular and cirriform appendages are also smooth. The palpi are
large, slightly tapered, and smooth. Body rather short and broad, about thirty-one
bristled segments, much tapered posteriorly, and furnished with a caudal rudder in the
shape of a thick style with a membranous flap, tapered from base to apex. In structure
it is délicate and brittle, and is tinted of a deep madder-brown both dorsally and ventrally.
Segmental eminence marked, but no distinct papilla is visible. Scales, fifteen pairs, thin
but tough, rounded in front, rest large and ovate, completely covered with minute spines,
but with a smooth edge; some cling firmly to the peduncles. Feet of considerable
length, dorsal division rudimentary ; bristles translucent, large, long, and acutely pointed,
with wide rows of spines like an Eqmsetum ; ventral division large, ovate at the tip, and
having a broad fan of very long slender bristles with long spinous regions and acute tips,
mostly bifid. Ventral cirrus comparatively long and slender.
Habitat.—Procured by the ‘ Triton ’ in August, 1882, at 600 fathoms ; at Station 2,
500 fathoms; in the tow-net at 300 fathoms, and again at,the surface.
' Length about 14 mm.
Head (Plate XXVIII, fig. 6) comparatively small, broadly ovoid, with a median
groove and two prominent anterior peaks. Both pairs of eyes are dorso-lateral in
position, their largest surface in the preparation being, lateral. Their large size and
the limited area of the head leave little of the lateral region free, viz. a small portion at
the peaks, the narrow line of separation between the pairs, and the brief space between
the last and the nuchal collar. No distinct trace of a corneal opacity is present. From
the contour of the head the anterior pair look forward and outward, the posterior outward
and upward. Both pairs are partially seen from the dorsum. In young examples
the eyes are considerably smaller. The long median tentacle is pale, slightly enlarged
immediately above the basal region (in spirit), then it tapers to the filiform tip. Its
surface is quite smooth, the median nerve-trunk being readily seen through its translucent
granular layer. The lateral tentacles are pale, subulate, and small, with a filiform tip
and a madder-brown basal region. They likewise are quite smooth. The palpi are
smooth, of moderate length, and somewhat thick, with comparatively short tapering tips.
They have a faint tinge of madder-brown at the base. The tentacular cirri, the upper of
which is, as usual, larger than the lower, have a similar form to the median tentacle.
Body covered by the large scales; of about thirty-one bristled segments, and comparatively
short and broad. I t is slightly narrowed in front, and tapers somewhat
rapidly posteriorly. The dorsum has a madder-brown hue, with transverse elliptical
markings in the middle, paler on the feet. Posteriorly the segments have very beautiful
patterns, the madder-brown ellipse being surrounded by a pale and somewhat crenate
line. The entire under surface is madder-brown, with a pale median band, and iridescent,
the darker region in front showing fine metallic lustre. The feet are also slightly tinted
of the same brownish hue, the ventral cirrus being thus rendered conspicuous, and
between its base and the body a pale transverse line occurs. The segmental eminence is
marked, but no distinct papilla is visible—a feature perhaps associated with the pelagic
habits of the species.
Posteriorly the body terminates in a single comparatively thick style, which arises
beneath the anus and to the left. I t remains nearly cylindrical from base to tip—which