Undella (Parundella) aculeata – synonym of Parundella caudata
Undella (Parundella) aculeata, forma longa – synonym of Parundella caudata
Undella (Parundella) caudata – synonym of Parundella caudata
Undella (Parundella) messinensis – synonym of Parundella messinensis
Undella attenuata – synonym of Undella hyalina
Undella bulla – synonym of Undella hyalina
Undella Claparèdei – synonym of Undella claparedei-group
Undella claparedei var. c – synonym of Undella claparedei-group
Undella claparedei var. d – synonym of Undella claparedei-group
Undella claparedei var. e globosa – synonym of Undella claparedei-group
Undella claparedei var. f – synonym of Undella claparedei-group
Undella claparedei var. g – synonym of Undella claparedei-group
Undella claparedei var. grandis – synonym of Undella grandis
Undella declivis – synonym of Undella hyalina
Undella dilatata – synonym of Undella hyalina
Undella filigera – synonym of Albatrossiella filigera
Undella globosa – synonym of Undella claparedei-group
Undella heros – synonym of Xystonellopsis heros
Undella heros var. gaussi – synonym of Xystonellopsis heros
Undella hyalina var. a – synonym of Undella hyalina
Undella hyalina var. b – synonym of Undella hyalina
Undella hyalina var. c – synonym of Undella hyalina
Undella hyalina, forma attenuata – synonym of Undella hyalina
Undella mammilata – synonym of Undella hyalina
Undella marsupialis – synonym of Undellopsis marsupialis
Undella marsupialis, forma subangulata – synonym of Undellopsis marsupialis
Undella marsupialis, forma subcylindrica – synonym of Undellopsis marsupialis
Undella media – synonym of Undella hyalina
Undella messinensis – synonym of Parundella messinensis
Undella messinensis var. a – synonym of Parundella caudata
Undella monocollaria – synonym of Amplectella monocollaria
Undella paradoxa – synonym of Xystonellopsis paradoxa
Undella parva – synonym of Undella hyalina
Undella peruana – synonym of Undella hyalina
Undella subacuta – synonym of Undella claparedei-group
Undella subacuta var. subcaudata – synonym of Undella claparedei-group
Undella subcaudata – synonym of Undella claparedei-group
Undella subcaudata subcaudata – synonym of Undella claparedei-group
Undella tricollaria – synonym of Amplectella nuda
Undella tricollaria – synonym of Amplectella tricollaria
Undella tridivisa – synonym of Amplectella tridivisa
Undellopsis (Undellicricos) nuda – synonym of Amplectella nuda
Undellopsis (Undellopsis) lineata – synonym of Undellopsis marsupialis
Undellopsis (Undellopsis) marsupialis – synonym of Undellopsis marsupialis
Undellopsis (Undellopsis) pacifica – synonym of Undellopsis marsupialis
Undellopsis cubitum – synonym of Undellopsis marsupialis
Undellopsis subangulata – synonym of Undellopsis marsupialis
Undellopsis tricollaria – synonym of Amplectella tricollaria
Uronychia antarctica – synonym of Uronychia transfuga
Uronychia uncinata – synonym of Uronychia transfuga