Definify.com
Webster 1913 Edition
Delthyris
‖
Del-thy′ris
,Noun.
[NL., fr. Gr.
δέλτα
the name of the letter Δ + τηύρα
door.] (Zool.)
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.