cyclobranchiata

from The Century Dictionary.

• In De Blainville's system of classification, an order of gastropodous mollusks, characterized by the circular disposition of the gills, represented by the chitons and limpets. The group as thus constituted is not now generally adopted.
• A suborder of prosobran-chiate gastropods, modified from the original group by the exclusion of the chitons or poly-placophorous mollusks, and consisting only of the limpets or docoglossate gastropods.