of the first cirrus.

_Caudal Appendages_, rather longer than the pedicels of the sixth
cirrus, composed of seven cylindrical, tapering segments, each with a
circle of very fine bristles on its summit.

The acoustic (?) sacks are situated some way below the basal
articulations of the first cirrus.

2. ALEPAS PARASITA.

ALEPAS PARASITA. _Sander Rang._ Man. des Mollusq., p. 364, Pl.
viii, fig. 5, 1829.[44]

ANATIFA UNIVALVIS. _Quoy_ et _Gaimard_. Annales des Sciences,
Nat., tom. x, p. 234, 1827, Pl. vii, fig. 8.

---- PARASITA. _Quoy_ et _Gaimard_. Voyage de l'Astrolabe, Pl.
xciii, 1834.

TRITON (ALEPAS) FASCICULATUS. _Lesson._ Voyage de la Coquille.
Mollusc. Pl. xvi, fig. 6, tom. ii, part I, 1830, p. 442.

[44] M. Sander Rang rejects the specific name "_univalvis_," as
signifying a generic character, and he has been followed in this
by MM. Quoy and Gaimard themselves. This, according to the Rules
of the British Association, would hardly have been a sufficient
reason, but it appears that _A. parasita_, like _A. minuta_, has
a pair of horny scuta or valves; and, therefore, the name
_univalvis_ is too obviously false to be retained. With respect
to the generic name Triton, I fully believe that it was applied
by Linnaeus to the cast-off exuviae of sessile Cirripedes.

_A. apertura non prominente, capituli longitudinis 2/3 aequante: scutis
corneis: longitudine tota ad 2 uncias._

Orifice not protuberant, equalling two thirds of the length of the
capitulum: scuta horny. Total length two inches.

Animal unknown.

Parasitic on Medusae, Mediterranean and Atlantic Oceans: south
shore of England(?)[45]

I have not seen this species, and have drawn up the above specific
character from the Plates and brief descriptions in the Voyages of the
Coquille and Astrolabe. M. Lesson thinks that his species differs from
that of MM. Quoy and Gaimard; but as the peculiar yellow colour of the
capitulum, general shape, short cirri, habits and range, are all common
to both, I believe that they are identical. There is, however, one
singular difference, namely, that the cirri are coloured bright blue in
the Plate in the Voyage of the Astrolabe, and yellowish in that in the
Voyage of the Coquille: this possibly may have resulted from the drawing
in the latter case having been made from a specimen long kept in
spirits.

M. Lesson says that there are seven p