Sentence Examples with the word discina

In the Ecardines, of which Lingula and Discina may be quoted as examples, the myology is much more complicated.

In Lingula and Discina the anus lies to the right in the mantle-cavity, but in Crania it opens medianly into a posterior extension of the same.

Other common genera are Spirifer, Chonetes, Athyris, Rhynchonellids and Terebratulids, Discina and Crania.

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Undue stress is often laid on the fact that Lingula has come down to us apparently unchanged since Cambrian times, whilst Crania, and forms very closely resembling Discina and Rhynchonella, are found from the Ordovician strata onwards.