Literature referred to
- Tiddeman , R. H. 1875 . “ The Geology of the Burnely Coalfield ” . In Mem. Geol. Surv. England & Wales & others
- Delépine , G. 1928 . Les Brachiopodes du Marbre Noir de Dinant . Mém. Mus. Hist. nat. Belg. , : 16 – 16 .
- Paeckelmann , W. 1930 . Die Brachiopoden des deutschen Unterkarbons . Abhandl. preuss. geol. Landesanst. N.F. , : 220 – 222 .
- Cope , F. Wolverson . 1933 . The Lower Carboniferous Succession in the Wye Valley Region of North Derbyshire . Journ. Manchester Geol. Assoc. , i ( 3 ) : 140 – 140 .