agnostus

[Gr. ἄγνωστος (agnostos) = unknown.] Palæont .: A genus of trilobites characteristic of the Lower Silurian rocks. A. trinodus (Salter) and A. pisiform is (Brongniart) are mentioned by Murchison, in his "Siluria," as occurring in Britain, the latter having before been known only in the Lower Silurian schists of Sweden. They are minute in size, and may be the larval form of some larger trilobite. They usually occur in groups, with nothing but the cephalic shield preserved. ǎg-nō-thër-i-ŭm, s. [Gr. ἀγνώς ( agnōs ) = unknown, and θηρίον ( thērion ) = animal.] Paleont. The name given by Kaup to a fo il mammal.