armature either in the stomach or on the genitalia. The hermaphrodite gland forms
a layer spread over the liver.
Numerous descriptions of various specie^ have been published. See especially
Bergh’s monograph referred to above.
The genus has been divided into Tritonia sensu stricto and Candiella. The former
comprises rather large and stout animals with broad radulge and small tubercles or
papillaa on the oral veil, whereas the name Candiella is given to smaller and more slender
forms which have a narrow radula but bear moderately long digitations on the oral veil.
But the two sections run into one another and cannot be regarded as having inore than
subgeneric rank, nor do the characters of a digitate veil and narrow radula always go
together. Candiella ingolfiana Bergh has a radula of 67 X 84.1.84, whereas Tritonia
challengeriana Bergh has one of only 48 X 45.1.45.
Marionia Vayssiere is distinguished from Tritonia by having the stomach armed
with hard plates. The processes on the oral veil are generally branched, and the
branchise are often very ample. This genus is frequent in the Mediterranean and warm
waters, but has not yet been recorded from the northern Atlantic.
Section Tritonia sensu stricto.
1. T. hombergii Cov.
(Pt. 7, Pam. 2, PI. 2.)1
Section Candiella.
2. T. plebeia J ohnston.
(Pt. 3, Pam. 2, PI. 3.)
3. T. lineata A. & H.
(Pt. 5, Pam. 2, PI. 4.)
4. T. alba A. & H.
(Pt. 8, PI. I, fig. 10.)' ./
The last species, on account of its remarkable radula, has at least as good a claim
to be the type of a sub-genus as Candiella.
[Two other species are recorded from the northern Atlantic but are little known.
Tritonia psoloides Aurivillius (see Vega Expedition, p. .381) has a warty and reticulate
back and a narrower radula (80.1.80) than T. hombergii. Candiella ingolfiana Bergh is
known from a single preserved specimen obtained in deep water, 61° 44' lat. N. and
27° long. W. I t is about 5 centimetres long, and as preserved bluish grey with
yellow colouring on the head, foot, and rhinophores. It has twelve to fourteen small
branchias and twelve digitations on the oral veil. The first lateral tooth of the radula
is denticulate.
Bergh (54, pp. 22—26) created the genus Atthila for a remarkable animal, found
1 The references are to the plates of the Monograph.
in deep water, 62° lat. N. 21° 36' long. W., which resembles Tritonia in many respects
but has the following peculiarities : (a) there are three rows of appendages on the dorsal
surface; (b) the oral veil is large but has a smooth margin; (c) the rhinophores are
perfoliate*p;.(d) in the buccal parts the edge of the jaws is smooth; the central tooth of
the radula and the first lateral are not denticulate. The structure of the liver and
hermaphrodite gland is not quite clear from the published description, but is apparently
not the same as in Tritonia. The only known species, Atthila ingolfiana Bergh, is said to
have been of a pale flesh colour when alive.]
F amily II. DORIDIDÆ CRYPTOBRAN CHI ATÆ.
Branchiæ retractile into a permanent pocket. Two spermatothecas.
Genus JiljDoris1 L.
Animals not hard, flattish, but. the back is usually moderately arched. The
dorsal surface is covered with tubercles or warts which are sometimes specially developed
round the openings of the branchiae and rhinophores. Tentacles often thick, grooved
projections. Foot broad. Mantle-margin not narrow. Radula broad and composed of
simply hamate teeth. No armature on the labial cuticle or the male genitalia.
This genus is distinguished by the shape, the tuberculate back, and the buccal parts.
As a rule there is no labial armature at all, and if traces of it are sometimes found
it is only rudimentary.
Sec. i. Staurodoris B ergh.
Tubercles large and club-like, sometimes connected by ridges and specially developed
so as to protect the branchiæ and rhinophores. Branchiæ usually pinnate or bipinnate.
In typical forms these characters are very distinct, but they vary considerably even
within the limits of one species.
1. D. verrucosa Cuv.
(Pt. 6, Pam. 1, PI. 11.) •
2. D. maculata Garstang.
(Pt. 8, PI. VIII, figs. 6, 7.)
Sec. ii. Archidoris Bergh.
. Tubercles smaller than in Staurodoiis and not. specially developed to protect the
branchiæ and rhinophores, though they sometimes form a circle round the pockets.
Branchiæ usually tripinnate, more rarely bipinnate.
1 Full references to the literature are given in the descriptions of the various species, pp. Ô6—99.