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Updated: June 23, 2025


Analogy seems to me to be rather in favour of, than against, the supposition that while only Ganoid fishes inhabited the fresh waters of our Devonian land, Amphibia and Reptilia, or even higher forms, may have existed, though we have not yet found them.

He felt almost aggrieved to find Walcott so vigorously acting the part of Comus as to have flung the ganoid all the way off to Colorado and far back into the Lower Trenton limestone, making the Pteraspis as modern as a Mississippi gar-pike by spawning an ancestry for him, indefinitely more remote, in the dawn of known organic life.

Finally, with respect to the 'Vertebrata', the same law holds good: certain types, such as those of the ganoid and placoid fishes, having persisted from the palaeozoic epoch to the present time without a greater amount of deviation from the normal standard than that which is seen within the limits of the group as it now exists.

Fran lowered the binoculars. He looked at Soames with a terrible hatred in his eyes. Soames went back to Gail, leaving the binoculars with the children. He found himself sweating. "When," asked Soames harshly, "were the mountains on the moon made? It's an interesting question. I just got an answer. They were made when there were three-toed horses and many ganoid fishes on the earth."

And it is in fresh water basins that we find seven genera of Ganoid fishes, remnants of a once preponderant order: and in fresh water we find some of the most anomalous forms now known in the world, as the Ornithorhynchus and Lepidosiren, which, like fossils, connect to a certain extent orders at present widely separated in the natural scale.

In the genera Dipterus and Diplopterus, as Hugh Miller pointed out, and in several other of the fringe-finned genera, as in Gyroptychius and Glyptolepis, the two dorsals are placed far backward, or directly over the ventral and anal fins. The Asterolepis was a ganoid fish of gigantic dimensions.

To him, the ganoid was a huge perplexity, none the less because neither he nor the ganoid troubled Darwinians, but the more because it helped to reveal that Darwinism seemed to survive only in England. In vain he asked what sort of evolution had taken its place. Almost any doctrine seemed orthodox.

This one, Lepidosteus, has a wide range in America, being found from Florida to Wisconsin. Another American ganoid is Amia calva, the dog-fish or bow-fin, which is very numerous in Western rivers. Both are voracious, but unfit for food.

For instance, some species of Trigonia, a great genus of shells in the secondary formations, survive in the Australian seas; and a few members of the great and almost extinct group of Ganoid fishes still inhabit our fresh waters. Therefore, the utter extinction of a group is generally, as we have seen, a slower process than its production.

They abandoned the defensive system of warfare and boldly took up the offensive. No doubt, like their descendants, the belemnites were exceedingly active and voracious creatures. FISHES AND AMPHIBIANS. In the Triassic and Jurassic, little progress was made among the fishes, and the ganoid was still the leading type.

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