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Or among the Teleostei in what respect is the 'Beryx' of the Chalk more embryonic, or less differentiated, than 'Beryx lineatus' of King George's Sound? Or to turn to the higher Vertebrata in what sense are the Liassic Chelonia inferior to those which now exist?
Or among the Teleostei in what respect is the Beryx of the Chalk more embryonic, or less differentiated, than Beryx lineatus of King George's Sound? Or to turn to the higher Vertebrata in what sense are the Liassic Chelonia inferior to those which now exist? How are the Cretaceous Ichthyosauria, Plesiosauria, or Pterosauria less embryonic, or more differentiated, species than those of the Lias?
On the Volga below Nijni Novgorod the sturgeon, and others of the same family, as also a very great variety of ganoids and Teleostei, appear in such quantities that they give occupation to nearly 100,000 people. The mouths of the Caspian rivers are especially celebrated for their wealth of fish. Siberia is emphatically the "Land of the North."
From the primitive fishes or Selachii, the earliest Gnathostomes, was developed the legion of the Ganoids. On the other hand, we have a great variety of specimens of this group in the fossil state, from the Upper Silurian onward. Some of these fossil Ganoids approach closely to the Selachii; others are nearer to the Dipneusts; others again represent a transition to the Teleostei.
Or among the Teleostei in what respect is the Beryx of the Chalk more embryonic, or less differentiated, than Beryx lineatus of King George's Sound? Or to turn to the higher Vertebrata in what sense are the Liassic Chelonia inferior to those which now exist? How are the Cretaceous Ichthyosauria, Plesiosauria, or Pterosauria less embryonic, or more differentiated, species than those of the Lias?
But considering the close relation of the Mudfish with the Ganoidei, and the wide differences between the Elasmobranchii and the Teleostei, I greatly doubt the propriety of separating the Dipneusta, as a class, from the other Pisces.
The Teleostei are modified Ganoidei. The Dipneusta gave rise to the Amphibia, which are the root of all other Vertebrata, inasmuch as out of them were developed the first Vertebrata provided with an amnion, or the Protamniota. The Protamniota split up into two stems, one that of the Mammalia, the other common to Reptilia and Aves.
Comparative anatomy and ontogeny show clearly that the Ganoids descended from the Selachii, and the Teleostei from the Ganoids. On the other hand, a collateral line, or rather the advancing chief line of the vertebrate stem, was developed from the earlier Ganoids, and this leads us through the group of the Dipneusta to the important division of the Amphibia.
Or among the Teleostei in what respect is the 'Beryx' of the Chalk more embryonic, or less differentiated, than 'Beryx lineatus' of King George's Sound? Or to turn to the higher Vertebrata in what sense are the Liassic Chelonia inferior to those which now exist?
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