Columbia subject headings:
Brachiopoda, Fossil--Great Britain.
Paleontology--Great Britain.
Paleontology--Ordovician.
Harvard subject headings:
Brachiopoda, Fossil--Great Britain.
Geology, Stratigraphic--Ordovician
Inarticulata, Fossil--England.
Inarticulata, Fossil--Wales.
Paleontology--England.
Paleontology--Great Britain
Paleontology--Ordovician
Paleontology--Wales.
Princeton subject headings:
Brachiopoda, Fossil--Great Britain.
Paleontology--Great Britain.
Paleontology--Ordovican.