Chapter VII

Classification of the naturalist not always correspondent with
the order of nature--Incongruous grouping of animals
in the invertebrate division--Rudimentary skeleton
of the cephalopods--Introduction of the vertebrate
type into creation--Ichthyolites of the carboniferous
rocks--Their state of keeping--Classification of fossil
fishes--Placoids--Ichthyodorulites--Ganoids--Their structure
exemplified in the megalichthys and holoptychius--Cranium of
megalichthys--Its armature of scales--Microscopic structure of
a scale--Skeleton of megalichthys--History of the discovery
of the holoptychius--Confounded with megalichthys--External
ornament of holoptychius--Its jaws and teeth--Microscopic
structure of the teeth--Paucity of terrestrial fauna in coal
measures--Insect remains--Relics of reptiles--Concluding
summary of the characters of the Carboniferous fauna--Results,

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