'Delthyris limestone' definitions:

Definition of 'Delthyris limestone'

From: GCIDE
  • Delthyris \Del*thy"ris\, n. [NL., fr. Gr. de`lta the name of the letter [Delta] + thy`ra door.] (Zool.) A name formerly given to certain Silurian brachiopod shells of the genus Spirifer. [1913 Webster]
  • Delthyris limestone (Geol.), one of the divisions of the Upper Silurian rocks in New York. [1913 Webster]