XX 
INTROBIJCTION. 
The accompanying Tables have been prepared, viz. Table A, pp.xviii, 
xix, showing the distribution in time of the genera and subgenera of 
the Nautiloidea contained in the British Museum, with the number 
of species assigned to each, under their respective Formations ; 
the large Table B indicating, approximately, the correlations of the 
Secondary and Tertiary rocks of England with those of part of the 
Continent of Europe. The purpose of this Table is to show as 
many as possible of the stratigraphical divisions referred to under 
the descriptions of the species. The principal works consulted in 
the compilation of this table are as follows : — for the English rocks, 
H. B. Woodward’s ‘ Geology of England and Wales ’ (1887) ; for 
those of France, de Lapparent’s ‘ Traite de Geologic ’ (1885) ; for 
those of Belgium, Mourlon’s ‘ Geologic de la Belgique ’ (1880-1881), 
and Vanden Broeck’s ‘ Esquisse Geologique et Paleontologique des 
Depots Pliocenes des Environs d’ Anvers’ (1876-1878) ; for those of 
Germany and Austria-Hungary, Credner’s ‘ Elemente der Geologic ’ 
(1887) ; for those of Switzerland and the Alps, lienevier’s ‘ Tableau 
des Terrains Sedimentaires ’ (1874), and other works. I am par- 
ticularly indebted to Mr. G. F. Harris, F.G.S., for valuable infor- 
mation regarding the correlation of the Tertiary rocks of England 
with those of Belgium and France, a subject to which he has 
devoted special attention. 
Since the publication of Part I. my attention has been directed 
to some of the structural characters of the NautilicUe. Amongst 
these may be mentioned the discovery of very distinct marks of the 
shell-muscle upon casts of several Carboniferous and Jurassic 
species k The results of a study of these interesting features have 
been published from time to time by myself, in conjunction with 
Mr. G. C. Crick, of the Geological Department of the British 
Museum, in the ‘Geological Magazine’ and in the ‘Annals and 
Magazine of Natural History.’ These results are all embodied in 
the present volume, at the pages indicated in the footnote at the 
bottom of this page. 
In a paper contributed to the ‘ Annals and Magazine of Natural 
History ’ (ser. 6, vol. v. 1890, p. 404) by Mr. Crick and myself, a 
See infra, pp. 106, 172, 214, 219., 225, 226 (figs. 15, 29, 42, 43, 46, 49, 50). 
