Visceral mass and shell sinistral; inferior pallial lobe very prominent, and transformed into a branchia.
Tadpoles (after they have cast their branchia or gills), newts, and rock fish can be used to the extent of six to the gallon.
First branchia on each side attached to second somite just in front and mesad of the first setigerous tubercle.
Shell conical, not spiral; inferior pallial lobe transformed into a branchia.
This has been called a branchial arm, not that it carried a branchia, but on account of its relation to the respiratory system.
On each side of the branchia is a series of lamellae, least in number in the Octopoda.
The second branchia attached just caudad of the first on the caudal region of somite III.