e-Edwards and Haime.
(23) 'Supplement to the Fossil Corals' (Palaeontographical Society).
Martin Duncan.
(24) 'Echinodermata or the Cretaceous Formation' (Palaeontographical
Society). Wright.
(25) 'Monograph of the Belemnitidae' (Palaeontographical Society).
Phillips.
(26) 'Monograph of the Trigoniae' (Palaeontographical Society).
Lycett.
(27) 'Fossil Cirripedes' (Palaeontographical Society). Darwin.
(28) 'Fossil Mollusca of the Chalk of Britain' (Palaeontographical
Society). Sharpe.
(29) 'Entomostraca of the Cretaceous Formation' (Palaeontographical
Society). Rupert Jones.
(30) 'Monograph of the Fossil Reptiles of the Cretaceous Formation'
(Palaeontographical Society). Owen.
(31) 'Manual of Palaeontology.' Owen.
(32) 'Synopsis of Extinct Batrachia and Reptilia.' Cope.
(33) "Structure of the Skull and Limbs in Mosasauroid
Reptiles"--'American Journ. Sci. and Arts, 1872.' Marsh.
(34) "On Odontornithes"--'American Journ. Sci. and Arts, 1875.'
Marsh.
(35) 'Ossemens Fossiles.' Cuvier.
(36) 'Catalogue of Ornithosauria.' Seeley.
(37) 'Paleontologie Francaise.' D'Orbigny.
(38) 'Synopsis des Echinides fossiles.' Desor.
(39) 'Cat. Raisonne des Echinides.' Agassiz and Desor.
(40) "Echinoids"--'Decades of the Geol. Survey of Britain.'
E. Forbes.
(41) 'Paleontologie Francaise.' Cotteau.
(42) 'Versteinerungen der Boehmischen Kreide-formation.' Reuss.
(43) "Cephalopoda, Gasteropoda, Pelecypoda, Brachiopoda; &c., of the
Cretaceous Rocks of India"--'Palaeontologica Indica,' ser. i.,
iii., v., vi., viii. Stoliczka.
(44) "Cretaceous Reptiles of the United States"--'Smithsonian
Contributions to Knowledge,' vol. xiv. Leidy.
(45) 'Invertebrate Cretaceous, and Tertiary Fossils of the Upper
Missouri Country,' 1876. Meek.

CHAPTER XVIII.

THE EOCENE PERIOD.

Before commencing the study of the subdivisions of the Kainozoic
series, there are some general considerations to be noted. In
the first place, there is in the Old World a complete and entire
physical break between the rocks of the Mesozoic and Kainozoic
periods. In no instance in Europe are Tertiary strata to be found
resting conformably upon any Secondary rock. The Chalk has invariably
suffered much erosion and denudation before the lowest Tertiary
strata were deposited upon it. This is shown by the fact that the
actually eroded surface of the Chalk can often be seen; or, failing
this, that we can