pulmobranchiæ

from The Century Dictionary.

• Gills or branchiæ modified into organs of aërial respiration; the respiratory apparatus peculiar to certain animals. The lung-sacs of air-breathing mollusks, as snails. See cut under Pulmonata.
• The lung-sacs of certain arachnidans, as spiders; the pulmotracheæ. See cuts under pulmonary and Scorpionidæ.