- Delthyris limestone
- Delthyris Del*thy"ris, n. [NL., fr. Gr. de`lta the name of the
letter [Delta] + thy`ra door.] (Zo["o]l.)
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]
The Collaborative International Dictionary of English. 2000.