THALASSIC
thalassic
(adjective) relating to the seas, especially smaller or inland seas; “deposits of sediment in gulfs and seas rather than in the ocean proper are known as thalassic deposits”- Scientific American
Source: WordNet® 3.1
Etymology
Adjective
thalassic (comparative more thalassic, superlative most thalassic)
of or relating to seas and oceans
pelagic
Usage notes
• Used more often of smaller, or inland seas, as opposed to oceanic.
Source: Wiktionary
Tha*las"sic, a. Etym: [Gr. (Geol.)
Definition: Of or pertaining to the sea; -- sometimes applied to rocks
formed from sediments deposited upon the sea bottom.
Source: Webster’s Unabridged Dictionary 1913 Edition