a, 366.
Valentiana, 371.
powers of burrowing, 337.

Loven, Dr., on the habits of the _Alepas squalicola_, 178.
on the homologies of Cirripedes, 26.

Lowe, Rev. R. T., on the fishes of Madeira and Japan, 106.
on the Cirripedes of Madeira, 65.

Macgillivray, Prof., on Conchoderma, 140.
on Lepas anserifera, 81.

_Malacotta_, 137.
_bivalvis_, 141.

Male Cirripedes, discussion on, 281.
of Ibla Cumingii, 189.
" quadrivalvis, 207.
of Scalpellum ornatum, 248.
Peronii, 270.
rostratum, 262.
villosum, 278.
vulgare, 231.
organs of generation in the Lepadidae, 55.

Mandibles, general description of, 41.

Martin St. Ange, on the affinities of Cirripedes, 1.
on a closed tube within the stomach, 45.
on the generative organs, 55.

Maxillae, general description of, 41.

Membrane covering valves, 30.

Metamorphoses, first stage, 9.
second stage, 13.
last stage, 14.

_Mitella_, Genus, 293.

Mouth, general description of, 39.
of young Cirripede, 22.
of the larva, first stage, 11.
last stage, 17.

Muscles, 39.
without striae in Anelasma, and in embryonic Cirripedes, 172.

Nerves, general system of, 46.
of Ibla Cumingii, 188.

Nomenclature of the parts of Cirripedes, 3.
Rules of, 293.

_Octolasmis_, 115.
_Warwickii_, 120.

OEsophagus, general description of, 44.

Orders of Cirripedes, 2.

Organs acoustic (?) general description of, 53.
of the larva of Lepas, 15.
female, of generation, in the Lepadidae, 56.
male, of generation, in the Lepadidae, 55.
olfactory, general description of, 52.

_Otion_, 137.
_auritus_, 141.
_Bellianus_, 141.
_Blainvillianus_, 141.
_Cuvieranus_, 141.
_depressa_, 141.
_Dumerillianus_, 141.
_Rissoanus_, 141.
_saccutifera_, 141.

Ova, 58.

Ovaria, incipient in the larva, 20, 24.
in the Lepadidae, 57.

Oviducts (supposed), 59.

Owen, Professor, on certain Entozoic Worms, 201.
on the Conchoderma Hunteri, 154.

Oxynaspis, Genus, 133.
celata, 134.

_Pamina_, 137.
_trilineata_, 146.

Peach, Mr., obligations to, 240.
on the movements of pedunculated Cirripedes, 33.

Peduncle, general description of, 31.
origin and homologies of, 21.

Penis, general description of, 56.
of Ibla quadrivalvis, 206.

_Pentalasmis_