Definitions
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- proper noun zoology, obsolete The lowest group of
Vertebrata , including theamphioxus , in which no skull exists.
Etymologies
Sorry, no etymologies found.
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Examples
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Opposed to the Acrania is the second division of the vertebrates, which comprises all the other members of the stem, from the fishes up to man.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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In the Acrania and Cyclostomes and the earlier fishes we can scarcely distinguish a real stomach; it is represented merely by the short piece from the branchial to the hepatic gut.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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In the alimentary apparatus there are the thymus-gland and the thyroid gland, the seat of goitre and the relic of a ciliated groove that the Tunicates and Acrania still have in the gill-pannier; there is also the vermiform appendix to the caecum.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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In the Cyclostoma -- a stage above the Acrania -- the fore end of the cylindrical medullary tube begins early to expand into a pear-shaped vesicle; this is the first outline of an independent brain.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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The Craniota descend directly from the Acrania, and these from the primitive Chordonia.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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There is no trace of these pairs of limbs in the Acrania and
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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The Amphioxus is the only surviving representative of the older and lower section, the Acrania
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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The lowest and earliest Vertebrates, the Acrania and
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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Acrania (Amphioxus) for the phylogeny of the Vertebrate stem.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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These important parts are wholly wanting in the two lowest classes of Vertebrates, the Acrania and Cyclostoma.
The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876
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