Lutarius, Adiect. That liueth in the mudde or does. vt, Lutariæ testudines. Plin. Cockles and shelfishe lyuing in the mudde.Lutarius mullus. Plin.
Lewis and Short: Latin dictionary
lŭtārĭus, a, um, adj. [2. lutum], of or be longing to mud. I.Living in mud: testudines, Plin. 32, 4, 14, 32.—II.Living on mud: mullus, Plin. 9, 17, 30, 65.