The Story of a Boulder (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1858 edition. Excerpt: ... 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--Ichtbyodorulites--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. The organic remains hitherto described belong to that large division of the animal kingdom instituted by Lamarck, to comprehend all those whose internal structure is supported by no vertebral column, and which are hence termed invertebrate. They are for the most part protected by a hard outer covering, or exo-skeleton, which assumes many different modifications. We have seen it in the calcareous cells of the little net-like fenestella, in the geometric cup of the stone-lily, in the, double case of the cypris, and in the shells of the mollusca. But the order of nature does not always exactly correspond with the classification of the naturalist. His system must necessarily be precise, formal, and defined. One tribe ends off abruptly, and is immediately succeeded by another, with different functions and structure, and dignified with a separate name. But in the order of...