Delthyris
Pronunciation : Del*thy"ris
Part of Speech : n.
Etymology : [NL., fr. Gr. de`lta the name of the letter thy`ra door.] (Zo?l.)
Definition : Defn: A name formerly given to certain Silurian brachiopod shells of the genus Spirifer. Delthyris limestone (Geol.), one of the divisions of the Upper Silurian rocks in New York.
Source : Webster's Unabridged Dictionary, 1913