from The Century Dictionary.
- Having lamellate gills; pertaining to the Lamellibranchiata, or having their characters.
- noun One of the Lamellibranchiata, as any ordinary bivalve mollusk. Also
from the GNU version of the Collaborative International Dictionary of English.
- noun (Zoöl.) One of the Lamellibranchia (also called Pelecypoda). Also used adjectively.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun any marine or freshwater
bivalve mollusk, of the class Lamellibranchia; includes the clams, scallopsand oysters
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
- adjective bivalve
from The American Heritage® Dictionary of the English Language, 4th Edition
[From New Latin Lāmellibranchia, class name : lamelli– + Latin branchia, gill; see branchia.]
Jackson's  work on the mechanical origin of characters in the lamellibranch molluscs.