Deep-sea forms also occur, but in spite of this the group is essentially pelagic.
In the shallower tropical waters, especially on the central ridge, considerable areas are covered by Pteropod ooze, a deposit consisting largely of the shells of pelagic molluscs.
The violent personalities of a pamphlet entitled Marie Joseph Chenier et le prince des critiques (1844), in reply to Jules Janin, brought him a six months' sojourn in La Pelagic, in the cell just quitted by Lamennais.
Fusus, Pyrula, Purpura, Murex, Nassa, Trophon, Voluta, &c. The float of the pelagic Janthina, to which the egg-capsules are attached, probably is also formed by the secretion of the pedal gland.
The odontophore also is remarkably developed, its lateral teeth being mobile, and it serves as an efficient organ for attacking the other pelagic forms on which the Heteropoda prey.
