124 DOTO ClNEREA.
DOTO OINBREA Trinchese.
Trinchese 1, p. 92, pi. lv. Vayssiere 1, pp. 102—106.
At different times I have seen at Plymouth three living specimens, probably referable
to this species, which is recorded from Genoa, Marseilles, and the Cape Verde Islands.
The animals are small, being rarely more than 5—6 mm. in length. The ground
colour of both the body and the cerata is buff or dull yellow, but the dorsal surface,
especially at the bases of the cerata, is mottled with dark brown or black. The amount
of this mottling (and consequently the general colour of the animal) varies greatly in
different individuals. The tips of the tubercles which the cerata bear are white, and
never dark as in D. coronata.
The frontal veil is somewhat ample and projects at the sides. The rhinophores are
rather long and the edges of their sheaths are crenulate. The foot is broad. There are
from four to six pairs of cerata, rather elongate and studded with small spherical tubercles
arranged rather irregularly in from three to five rows. The terminal tubercle is about
twice as large as the others. The radula is a row of from eighty to ninety teeth, which
have a few (two to three) indistinct and irregular denticles at the sides of the median
cusp. The jaws are very thin and delicate and the cutting edge is smooth.
In many respects this species resembles D. cuspidata, but is distinguished from it by
the shape of the cerata. In D. cuspidata (D. cornalias, etc.) these are said to bear elongate
and very prominent tubercles; in D. cinerea the tubercles are small and spherical and the
cerata have somewhat the appearance of elongated and compact bunches of currants. I
think the species is valid, but it is a very inconspicuous little animal. I t can easily be
distinguished from D. coronata by the white tips of its papillge.
DOTO PINNATIFIDA (Mont.).
This species seems to exist in several varieties, of which I have noticed three at
Plymouth.
(1) Var. splendida (= Doto splendida Trinchese). This is probably the young of the
typical form.' It varies from white to light drab colour, and is punctuated, especially on
the back, with distinct black dots, which are not at all confluent. The ridges in front of
the rhinophores are absent and the lateral papillae are developed only imperfectly. The
cerata are elongate and almost cylindrical; the oral veil is narrow.
This form is not infrequent at Plymouth. All the specimens which I have seen were
quite small, not exceeding 5 mm. in length.
(2) Var. nigra. This variety is produced by the multiplication and coalition of the
dark markings found on the typical D. pinnatifida. The colour thus becomes deep dark
grey or black, either uniform or with lighter mottlings. But the sole of the foot, the anal
papilla, and the rhinophores remain of a clear bright yellow, the rhinophores contrasting
vividly with their dark sheaths. The ridges on the oral veil are distinct, but the papillse
on the sides of the body are not well developed. The rim of the oral veil is usually
yellowish. The margin of the rhinophore sheaths is deeply jagged. The jaws are very
DOTO PINNATIFIDA. 125
thin and the radula consists of about seventy teeth, bearing a moderately high central
cusp and two or three lateral denticles.
I do not think that this is Doto obscwra described by me from the Cape Verde Islands.
It may, however, be a dark variety of D. aurea Trinchese, in which the reticulate violet
pattern has almost obliterated the yellow background.
(3) Var. papiUifera.. Three specimens from Plymouth, nearly a centimetre long.
The coloration, cerata, etc., are typical of the species as described by Alder and Hancock,
but there are numerous papillaa on the back, each with a black spot at the tip ; and there
are two or in some places three rows of such papillae on the sides. The rhinophore
sheaths are ample in front, but slit behind, and bear two or three papillae. All these
papillae are too long to be called tubercles, and are half or even three quarters of
a millimetre in height. The anal papilla is very large.
The buccal mass is very small and the radula minute, though it contains more than
one hundred closely fitting teeth. The teeth bear at least three denticles on each side of
the central cusp and perhaps other accessory denticles and ridges; but it is difficult to
get a distinct view of any tooth, even under the highest power.
This form is probably a variety of D. pinnatifida with the tubercles more developed.
All the proportions of the animal are larger than those described by Alder and Hancock,
and it is possibly merely the normal adult form.
CUMANOTUS Odhner.
Odhner 1, pp. 29, 80, and 101—-102. Eliot 1, pp. 361—363, and Eliot 3.
The genus Gwmanotus was created by Odhner in 1907.. The British species referable
to it, G. beanmontiy had previously been described as an aberrant Goryphella, but the
establishment of a special genus is quite justified. Cumavotus is allied to Goi'ypliella
inasmuch as it has unperfoliate rhinophores, tentacular angles to the foot, a triseriate
radula, and denticulate jaws. But it also possesses the following special characters:
(1) the oral tentacles are very small and connected by a cutaneous fold which runs across
the head and forms an oral veil; (2) there are several, at least three, rows of cerata in
front of the rhinophores; (3) the verge is deeply grooved, and there is a bursa copulatrix,
the entrance to which bears on its upper and lower margin a circular pad armed on the
periphery with twelve small cones terminating in hooks.
CUMANOTUS BBAUMONTI (Eliot).
|||^ 3 | G.oryphella beaumonti Eliot.
(Plate VIII, figs. 1—5.)
I have not seen the animal alive myself, but Mr. Beaumont, to whom the species is
dedicated, has kindly supplied me with the following notes:
“ Eolid from Barn Pool ^Plymouth').—Length 16 mm., but looks as if the posterior