Testaceous

[T]hey were burnt, or only baked in Oven or Sunne: According to the ancient way, in many bricks, tiles, pots, and testaceous works […]

Source: wiktionary

It has a very large head, in proportion to its body, all covered with a shell, like other testaceous Animals […]

Source: wiktionary

Tyrian garbs, / Neptunian Albion's high teſtaceous food [i.e., oysters], / And flavour'd Chian wines with incenſe fum'd / To ſlake Patrician thirſt: for theſe, their rights / In the vile ſtreets they proſtitute to ſale; / Their ancient rights, their dignities, their laws, / Their native glorious freedom.

Source: wiktionary

The Ship-VVorm of Jamaica. This inſect is extremely deſtructive to all the ſhips that anchor for any time in the harbours of Jamaica, or in any other part vvithin the tropics: They cut vvith great facility through the planks, and burrovv a conſiderable vvay in the ſubſtance of them, incruſtating the ſides of all their holes vvith a ſmooth teſtaceous ſubſtance[…].

Source: wiktionary