INTRODUCTION: 
Derrattep accounts of three families only of English Cretaceous Lamellibranchs 
have hitherto been given, namely, the Trigoniidx by Lycett, and the Nuculidee and 
Nuculanide by Gardner. Numerous species, however, belongmg to various 
families, were described and figured by J. and J. de C. Sowerby in the ‘ Mineral 
Conchology,’ and a few also by Parkinson im his ‘ Organic Remains of a Former 
World. A number of works, dealing primarily with the stratigraphy of the 
Cretaceous beds, also contain descriptions and illustrations of Cretaceous Lamelh- 
branchs from certain districts or from special horizons. One of the earliest of 
these is ‘The Fossils of the South Downs; or, Illustrations of the Geology of 
Sussex,’ by Gideon Mantell (1822), in which a number of Lamellibranchs from the 
Gault and Chalk of the south-east of England are described and figured; but 
unfortunately the figures are not very satisfactory, and in many cases the type- 
specimens are now missing; nevertheless, with the aid of other examples collected 
from the same localities, it is usually possible to discover the characters of 
Mantell’s species. 
Another early work dealing with a special district is the ‘ Illustrations of the 
Geology of Yorkshire,’ by John Phillips (1829), in which a few Lamellibranchs 
from the Speeton Clay are figured and others recorded. In ‘An Outline of the 
Geology of Norfolk,’ by 8S. Woodward (1833), the more important species from the 
Norwich Chalk are illustrated, but descriptions are not given. 
In Fitton’s great memoir (1836) on ‘The Strata between the Chalk and the 
Oxford Oolite in the south-east of England,’ many species of Lamellhbranchs, 
chiefly from Blackdown, are excellently figured and briefly described by J. de C. 
Sowerby; and most of the type-specimens are now preserved in the Bristol 
Museum. An account of the more important Lamellibranchs from the Lower 
Greensand of the Isle of Wight and of the Weald is given by Edward Forbes 
(1845) in a paper entitled ‘Catalogue of Lower Greensand Fossils in the Museum 
of the Geological Society,’ Part I. Most of the specimens therein described may 
still be seen in the Society’s Museum. 
Dealing with almost the same area as Mantell’s work is the later publication of 
