Ostraceous

That in the smaller jar is of the least consequence, being a mere unconnected formless fragment of a brown colour; while the other (which is figured) as grown over the concavity of a small ostraceous bivalve shell (fig. 26, b), and is of a lighter colour, but at once reveals the structure and habitat of the sponge, although, from being only a fragment with none of the surface left, it fails to afford its general form.

The Yoma range, according to the geological note in William's map of Pegu, is composed of brown or grey slate clay, with thin layers of bituminous limestone, containing fossil ostraceous remains, frequently alternating with, and entering into, beds of argillaceous sandstone, generally soft and friable, although stiff and hard in places.

Not only these annular, serpiginous, and polycyclic outlines, but particularly imbricated forms as well as ostraceous lesions are excellent dermatologic examples of regular, chronologic, phasic alternation between sensitivity and relative immunity.

Rupioid, elephantine, and ostraceous psoriasis are special forms of plaque psoriasis characterized by gross hyperkeratosis.