Fixed to the same spot in the ocean as the tree to the land, the nutritive surface of the poriferous animal is always in contact with the water. |
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In many specimens the anterior petals are delicate and the anterior poriferous zone narrows markedly towards the apical system. |
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No nervous filaments were ever discovered in a poriferous animal. |
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Their outer ends are covered over by a dermal poriferous membrane. |
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