pneumobranchiata

from The Century Dictionary.

• An order of gastropods, including those which breathe air in a closed chamber lined with pulmonic vessels: applied by J. E. Gray to the typical pulmonates or pulmonifers, and including most of the inoperculate landshells as well as the fresh-water forms related to them
• In Lamarck's classification (1819), a section of gastropods, containing his family Limacea.
• In Gray's classification (1821), a subclass of Gasteropodophora, comprising all terrestrial gastropods, and divided into Inoperculata and Operculata.