A MONOGKAPH 



BRITISH FOSSIL BRACHIOPODA. 



THOMAS DAVIDSON, LL.D., F.R.S., F.L.S., F.G.S., 



VICE-PRESIDENT OF THE PALaiONTOGRAPHICAL SOCIETY; MEMBER OF THE GEOLOGICAL SOCIETIES OF FEANCE, BELGIUM, 



EDINBURGH, GLASGOW, AND OF CORNWALL; FOREIGN MEMBER OF THE PEOVINCIAL INSTITUTE OF FEANCE ; OF THE 



L1NNEAN SOCIETY OF NORMANDY; CORRESPONDING MEMBER OF THE IMPERIAL ACADEMY OF SCIENCES OF ST. 



PETERSBURG; OF THE IMPERIAL MINERALOGICAL SOCIETY OF ST. PETERSBURG; OF THE IMPERIAL SOCIETY 



OF NATUEALISTS OF MOSCOW; OF THE EOYAL ACADEMIES OF BELGIUM AND BAVAEIA ; OF THE ROYAL 



SOCIETY OF HOLLAND, HAAELEM ; OF THE EOYAL SOCIETY OF LIEGE; OF THE ACADEMY OF ST. 



LOUIS ; OF THE AMEEICAN PHILOSOPHICAL SOCIETY, PHILADELPHIA ; OF THE INSTITUTE OF 



ALBANY, UNITED STATES; OF THE ZOOLOGICAL SOCIETY OF VIENNA; OF THE PALJ30NTO- 



GRAPHICAL SOCIETIES OF BELGIUM AND OF SWITZEELAND ; OF THE MALACOLOGICAL 



SOCIETY OF BELGIUM ; HON. MEMBER OF THE GEOLOGISTS' ASSOCIATION, 



LONDON ; OF THE DUDLEY AND MIDLAND GEOLOGICAL AND SCIENTIFIC 



SOCIETY; OF THE NATURAL HISTOEY SOCIETY OF GLASGOW; AND 



OF THE YORKSHIRE PHILOSOPHICAL SOCIETY, ETC. ETC. 



VOL. Y. 



SILURIAN AND DEVONIAN SUPPLEMENTS. 



GENERAL SUMMARY, WITH CATALOGUE AND INDEX OF 

 THE BRITISH SPECIES. 



LONDON: 

 PRINTED FOE THE PAL^ONTOGRAPHICAL SOCIETY. 



1882—1884. 



