The Insects were few, and, as I have said above, of a kind which seeks a moist atmosphere, or whose larvae live altogether in water.  They are not usually well preserved, as will be seen from the broken character of the one here represented, although the wood-cut is made from a better specimen than is often found.  We have, however, remains enough to establish unquestionably the fact of their existence in the Carboniferous period, and to show us that the type of Articulates was already represented by all its classes.

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Not so with the Vertebrates.  Fishes abound, but their class still consists, as before, of the Ganoids, those fishes of the earlier periods built on the Gar-Pike and Sturgeon pattern, and the Selachians, represented now by Sharks and Skates.  In the Carboniferous period we begin to find perfectly preserved specimens of the Ganoids, and the adjoining wood-cut represents such a one.  Of the old type of Selachians we have again one lingering representative in our own times to give us the clue to its ancestors,—­as the Gar-Pike explains the old Ganoids, and the Chambered Nautilus helps us to understand the Chambered Shells of past times.  The so-called Port-Jackson Shark has features which were very characteristic of the Carboniferous Sharks and are lost in the modern ones, so that it affords us a sort of link, as it were, and a measure of comparison, between those now living and the more ancient forms.  It is an interesting fact that this only living representative of the Carboniferous Shark should be found in New Holland, because it is there, in that isolated continent, left apart, as it would seem, for a special purpose, that we find reproduced for us most fully the character of the Animal Kingdom in earlier creations.

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The first Mammalia in the world were pouched animals, having that extraordinary attachment to the mother after birth which characterizes the Kangaroo.  In New Holland almost all the Mammalia are pouched, and have also the imperfect organization of the brain, as compared with the other Mammalia, which accompanies that peculiar structural feature; and although the American Opossum makes an exception to the rule, it is nevertheless true that this type of the Animal Kingdom is now confined almost exclusively to New Holland.  Whether this living picture of old creations in modern garb was meant to be educational for man or not, it is at least well that we should take advantage of it in learning all it has to teach us of the relations between the organic world of past and present times.

There were a great variety of the Selachians in the Carboniferous period.  The wood-cuts below represent a tooth and a spine from one of the most characteristic groups, but I have not thought it worth while to enumerate or to figure others here, for there are no perfect specimens, and their structural differences consist chiefly in the various form and appearance of the teeth, scales, and spines, and would be uninteresting to most of my readers.  I would refer the more scientific ones, who may care to know something of these details, to my investigations on Fossil Fishes, published many years since under the title of “Recherches sur les Poissons Fossiles.”