eastern coast of England, where it is found under stones near low-water mark; sometimes
four or five under one stone. From its small size, it appears to have escaped the notice of
naturalists, or it may have been passed over as the young of D.pilosa. We have few records
of its capture on the western coasts, where its place seems to be taken by nearly allied
species.
Doris aspera comes very near the D. muricata of Müller, from which it differs principally
in its smaller size, rather smaller tubercles, and almost constant white colour. There is,
however, a group of species in this section of Doris so nearly resembling each other, that it
requires more detailed characters than those given by Müller to discriminate them. D.fiisca
of Fabricius (a white species), and D. acufiuscula of Möller, appear to be very nearly allied to
D. aspera. Our D. proxima is also very closely related.
The Doris aspera of Macgillivray must be something different from ours, as he describes
it as having two small oral tentacles and the branchiae retractile. It was probably a very young
white variety of D. tubercidata.
This is comparatively an active animal, more restless than most of its congeners. When
kept alive for observation, it frequently floats inverted at the surface of the water, and, like
most of the littoral Dorides, it is apt to creep out of the water, and, if left over night, will often
be found dead and dried up in the morning on the side of the glass.
It spawns in May, June, and July. The spawn is deposited in a narrow coil of two or
sometimes three volutions, and is from a quarter to four tenths of an inch in diameter. The
eggs are white, and rather thinly scattered through the gelatinous envelope without apparent
order.
Figs. 1, 2, 3. Doris aspera, different views.
4. A dorsal tentacle.
5. A branchial plume.
6. A portion of the cloak, much enlarged.
7. Spicula.
8. Spawn.
9. A portion of the same, shewing the arrangement of the eggs.
Figs. 10 to 16.
DORIS PROXIMA, Alder and Hancock.
D. elliptica, flava ; pallio tuberculis validis, ellipticis; branchiis 11 pinnatis, non-retractilibus, anum
haud propinque cingentibus; capite velato.
Hub. Among rocks and sea-weeds between tide-marks. Birkenhead, J. Price,' Esq.
Body half an inch in length, elliptic-oblong, not much depressed, of a deep yellow or
orange colour, varying in some specimens to pale yellow or white. Cloak covered with stout, sub-
clavate, or elliptical bluntly-pointed tubercles, set at a little distance apart, and mixed with
smaller ones. The spicula appear through the skin, radiating from the tubercles. Dorsal tentacles
linear, slightly enlarged above, and obtusely pointed, with about fifteen laminae reaching
nearly to the base of the tentacle. They are usually of an orange-colour, deeper in shade
than the cloak. The margins of the cavities are smooth. Branchial plumes eleven, the two
posterior ones on each side small, yellowish, simply pinnate; the pinnae are about six in
number, of irregular length, and the plumes abruptly pointed: they are set in a small circle
scarcely so close to the anus as in the preceding species. Head with a broad veil, having a
large opening for the protrusion of the mouth. Foot rather broad, a little truncated in front,
and rounded behind; orange-yellow, the liver appearing through the centre of a purplish
colour, and extending much forward. Anterior margin with a frontal lamina.
The spicula are of various sizes, fusiform, with blunt points, and more or less bent, with
a'short spur or tubercle at the bending, which is usually »nearer one end. So far as we have
seen, none of the spicula are crucial or triradiate.
This at first sight appears to be a critical species, approaching as it does in external
characters very closely to D. aspera, with which we were at one time inclined to unite it, but
a minute analysis brings out several points of difference which we think would alone justify us
in considering it distinct; but the number and character of the lingual spines* at once
establish its right to rank as a species; indeed the tongue differs so widely from that of D.
aspera and its allies, that some naturalists might be disposed to consider them generically
distinct. The best external character is the form of the tubercles, which in this species are
elliptical or fusiform and obtusely pointed at the top, and not flatly rounded as in D. aspera;
the tentacles, too, have more numerous laminae and are thicker towards the top, and the liver,
* See PI. 46.