pelta

1. (historical) A small shield, especially one of an approximately elliptical form, or crescent-shaped.Examples: "Xenophon also mentions bronze peltae, but probably (like hoplite shields) they were only faced with a thin covering of bronze."; "The other subject illustrated in these scenes of silens carrying peltas appears to be a battle."; "After the Celtic invasion of Greece and the subsequent removal of some Celts (the Galatians) to Asia Minor in the 270s, Greek light troops seem to have stopped using the pelta, and adopted instead the large, oval Celtic shield with a central spine."historical

2. (art, historical) A crescent-shaped design used in mosaics.Examples: "A pattern of red and blue peltae on a white ground, arranged in groups of four with two peltae placed back to back and one at each end facing inward, forms the outer border on the east side of the mosaic."; "Evidently it was a deliberate choice to select from the repertory of opus sectile, often extremely figurative, only those decorative motifs that were amenable to sixteenth-century architectural classicism, like the peltae on the Farnese tables, which were still used for the seventeenth-century pavement of the Confessio of St Peter's."; "Surrounding the square frame of round-tongued double guilloche is a broad white band with large lozenges (two on each side), outlined dark grey, with their acute angles terminating in voluted peltae with undulating spurs on their roundels."historical

3. (botany) A flat apothecium with no rim.Examples: "The calyx is composed of five linear spreading sepals J inch long and attached to the sides of the inferior ovary are four bracts, two of which, the anterior and posterior, remain abortive, whilst the two lateral ones develop into large rounded flattened discs (peltae) attached at the centre."

4. (microbiology) A crescent-shaped sheet of microtubules that encircles the base of the flagella of a protozoan.Examples: "A striated parabasal fibre is closely associated with a large parabasal golgi system; a dense pre-axostylar fibre connects to the axostyle, which is a curved sheet of microtubules that encloses the nucleus and extends to (or protrudes from) the posterior end of the cell; the same pre-axostylar fibre links to the pelta, which is a sheet of microtubules that curves around within a sort of collar that encloses the flagellar bases before turning back to meet the axostyle […]"; "The pelta is a crescent-shaped sheet also formed by microtubules, and it overlaps with the axostyle in the anterior region of the cell. The pelta supports the wall of the anterior region of the cell and the flagellar canal from which the flagella emerges."; "The anterior semi-circular pelta surrounds the basal body area and the axostyle forms the longitudinal axis of the cell."