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Same as Spicula.

Any small calcareous or siliceous body found in the tissues of various invertebrate animals, especially in sponges and in most Alcyonaria.

Spicular.

A minute needlelike body, siliceous or calcareous, found extensively in Alcyonaria and other invertebrates; a minute-pointed process.

A fine, erect point.

An acicular crystal.

See spiculum (1st def.).