ll, Miocene strata of.
_Murchisonia; gracilis_.
_Murex.
Muschelkalk.
Musk-deer.
Musk-ox.
Musk-sheep.
_Myliobatis Edwardsii_.
_Mylodon; robustus_.
_Myophoria; lineata_.
_Myriapoda_ of the Coal.

_Nassa_.
_Natatores_.
_Natica_.
_Nautilus; Danicus; pompilius_.
Neanderthal skull.
Neocomian series.
_Neolimulus_.
_Nerinoea; Goodhallii_.
_Nerita_.
_Neuroptera_.
_Neuropteris_.
Newer Pliocene.
New Red Sandstone.
Newts.
Niagara Limestone.
_Nipadites; ellipticus_.
_Noeggerathia_.
Norwich Crag.
_Nothosaurus; mirabilis_.
_Notidanus_.
_Numenius gypsorum_.
_Nummulina; loevigata; pristina_.
_Nummulitic Limestone_.

Oak.
_Obolella; sagittalis_.
Odd-toed Ungulates.
_Odontaspis_.
_Odontopteris; Schlotheimi_.
_Odontopteryx; toliapicus_.
_Odontornithes_.
_Ogygia; Buchii_.
Older Pliocene.
_Oldhamia; antiqua_; slates of Ireland.
Old Red Sandstone; origin of name; of Scotland; relations of,
to Devonian.
_Olenus; micrurus_.
Oligocene.
_Oligoporus_.
Olive-shells.
_Omphyma_.
_Onchus; tenuistriatus_.
Oneida Conglomerate.
_Onychodus; sigmoides_.
Oolitic limestone, structure of; mode of formation of.
Oolitic rocks (_see_ Jurassic).
Ooze, Atlantic.
_Ophidia_; of the Eocene.
_Ophiuroidea_, of the Lower Silurian; of the Upper Silurian;
of the Carboniferous; of the Trias; of the Jurassic.
Opossum.
_Orbitoides_.
Oriskany Sandstone.
_Ormoxylon_.
_Orohippus_.
_Orthis; biforata; Davidsoni; elegantula; flabellulum; Hicksii;
lenticularis; plicatella; resupinata; subquadrala; testudinaria_.
_Orthoceras; crebriseptum_.
_Orthonota_.
_Orthoptera_.
_Osmeroides; Mantelli_.
_Osmerus_.
_Ostealepis_.
_Ostracode_ Crustaceans of the Cambrian; of the Lower Silurian;
of the Upper Silurian; of the Devonian; of the Carboniferous;
of the Permian; of the Trias; of the Jurassic; of the Cretaceous.
_Ostrea acuminata; Couloni; deltoidea; distorta; expansa, gregarea;
Marshii_.
_Otodus; obtiquus_.
_Otozamites_.
_Otozoum_.
_Oudenodon; Bainii_.
_Ovibos moschatus_.
Oxford Clay.
_Oxyrhina; xiphodon_.
Oysters.

_Pachyphyllum_.
_Paloearca_.
_Paloeaster; Ruthveni_.
_Palasterina; primoeva_.
_Paloechinus; ellipticus_.
_Paloeocaris; typus_.
_Paloeocoma; Colvini_.
_Paloeocoryne_.
Palaeolithic man, remains of.
_Paloeomanon_.
_Paloeoniscus_.
_Paloeontina Oolitica_.
Palaeontological evidence as to Evolution.
Palaeontological record, imperfection of the.
Palaeontology, definition of.
_Paloeonyctis_.
_Paloeophis; toli