Families
1
Arbaciidae
26
Arcidae
2
Cassidulidae
1
Cerithiidae
4
Faviidae
1
Lingulidae
1
Meandrinidae
3
Mellitidae
1
Ocypodidae
1
Phacopidae
1
Rhizangiidae
1
Scaphitidae
1
Siderastreidae
1
Toxopneustidae