r.) _Brugiere._ Encyclop. Meth. (des Vers), 1789.

PENTALASMIS DENTATUS (var.) _Brown._ Illust. Conch., Pl. lii, fig.
5.

ANATIFA . . . . . _Martin St. Ange._ Mem. sur l'organisation des
Cirripedes, 1835.

[24] As this, though the commonest species, has never been
defined, I give only a few synonyms and references, it being
quite impossible to distinguish, in any published description,
this species from _A. Hillii_ of Leach; this latter species I
recognise under this name only from having authentic specimens
from the British Museum, as Leach overlooked every one of the
real diagnostic characters.

[25] I have used, in conformity with botanists, the mark of
interjection, to show that I have seen an authentic specimen.

_L. valvis aut laevibus aut delicate striatis: e duobus scutis, dextro
solum dente interno umbonali instructo; pedunculi parte superiore
fusca._

Valves smooth, or delicately striated. Right-hand scutum alone furnished
with an internal umbonal tooth: uppermost part of peduncle
dark-coloured.

Filaments, two on each side.

Var. (_a_). Fig. 1. Scuta and terga with one or more diagonal lines of
dark greenish-brown, square, slightly depressed marks.

Var. (_b_). (Fig. 1 _b._) Carina strongly barbed.

Extremely common; attached to floating timber, vessels,
sea-weed, bottles, &c., and to each other, in the Atlantic
Ocean, Mediterranean, West Indies, Indian Ocean, Philippine
Archipelago, Sandwich Islands, Bass's Straits, Van Diemen's
Land.

_General Appearance._--Valves white, more or less translucent and thick,
with a tinge of blueish-grey, from the underlying corium; sometimes
brownish cream-coloured, rarely with a tint of purple. Surfaces smooth,
with traces of very fine lines radiating from the umbones, sometimes
rather plain on the basal part of the scuta. Length in proportion to the
breadth of the capitulum variable, owing to the varying degree to which
the scuta and terga have their apices produced. _Scuta_ with the
occludent margin either considerably curved or nearly straight. The
internal tooth of the right-hand scutum, close to the umbo, varies in
size and form, being either pointed, square, or obliquely truncated on
either side, or it has a notch on the summit; internal basal rim of the
scuta either plainly developed or nearly absent. In many specimens (Pl.
I, fig. 1), on the scuta, or on the scuta and terga, (and someti