eculiar curved position which the animal's body occupies
within the capitulum, I have found it far more convenient (not to
mention the confusion of nomenclature already existing) to apply the
term Rostral instead of ventral, and Carinal instead of dorsal, to
almost all the external and internal parts of the animal. Cirripedes
have generally been figured with their surfaces of attachment downwards,
hence I speak of the lower or Basal margins and angles, and of those
pointing in an opposite direction as the Upper; strictly speaking, as we
shall presently see, the exact centre of the usually broad and flat
surface of attachment is the anterior end of the animal, and the upper
tips of the Terga, the posterior end of that part of the animal which is
externally visible; but in some cases, for instance in Coronula, where
the base is _deeply concave_, and where the width of the shell far
exceeds the depth, it seemed almost ridiculous to call this, the
anterior extremity; as likewise does it in Balanus to call the united
tips of the Terga, lying deeply within the shell, the most posterior
point of the animal, as seen externally.

I have followed the example of Botanists, and added the interjection [!]
to synonyms, when I have seen an authentic specimen bearing the name in
question.

Every locality, under each species, is given from specimens ticketed in
a manner and under circumstances appearing to me worthy of full
confidence,--the specific determination being in each case made by
myself.

CLASS--CRUSTACEA. SUB-CLASS--CIRRIPEDIA.

FAMILY--LEPADIDAE.

_Cirripedia pedunculo flexili, musculis instructo: scutis[3] musculo
adductore solummodo instructis: valvis caeteris, siquae adsunt, in annulum
immobilem haud conjunctis._

Cirripedia having a peduncle, flexible, and provided with muscles.
Scuta[3] furnished only with an adductor muscle: other valves, when
present, not united into an immovable ring.

Metamorphoses; larva, first stage, pp. 9-12; larva, second
stage, p. 13; larva, last stage, p. 14; its carapace, ib.;
acoustic organs, p. 15; antennae, ib.; eyes, p. 16; mouth, p. 17;
thorax and limbs, p. 18; abdomen, p. 19; viscera, ib.; immature
cirripede, p. 20; homologies of parts, p. 25.

Description of mature Lepadidae, p. 28; capitulum, ib.; peduncle,
p. 31; attachment, p. 33; filamentary appendages, p. 38; shape
of body, and muscular system, p. 39; mouth, ib.; cirri, p. 42;