Umbo

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Related to umbos: Umbo of tympanic membrane

umbo

[′əm·bō]
(anatomy)
A rounded elevation of the surface of the tympanic membrane.
(invertebrate zoology)
A prominence above the hinge of a bivalve mollusk shell.

Umbo

 

the iron central boss of a shield, which protected the warrior’s hand. Under the hemispherical or conical umbo was a crosspiece by which the shield was held. Shields with umbones were widely used in ancient Greece and Rome and in medieval Europe and Rus’.

References in periodicals archive ?
Useful features for distinguishing larvae of the Ostreidae from those within other families of bivalves include asymmetry of left and right valves associated with a pronounced umbo of the left valve; one or two provincular teeth on each side of the provinculum; and a fasciole with a corresponding notch on the left valve.
Concha pequena, solida, trapezoidal, inequilateral con los umbos anteriores, los bordes dorsal posterior y ventral son casi paralelos, el borde anterior algo concavo en la region umbonal y redondeado en el resto, el borde posterior ampliamente redondeado; charnela con ligamento externo y un pequeno resilio, valva derecha con tres dientes cardinales,un lateral anterior y otro posterior, la valva izquierda con dos cardinales y dos laterales; escultura con 11 a 13 costillas radiales prominentes de aspecto nodular escamoso, los interespacios son anchos y algo profundos; periostraco pardo claro y color externo de la concha blanco amarillento, interior blanco a veces con manchas cafe y con los surcos producidos por la escultura externa, los bordes internos son crenulados.
violacea individuals at Emo were broken, the region encompassing the umbo and hinge ligaments (hinge plate), especially the posterior cardinal teeth (PCT), was the most abundant and intact shell feature throughout the entire Emo B.
Sculpture of the umbo typically, consisting of concentric double waves, rounded in front and beaked behind, parallel to the shell's growth lines (Fig.
At this time preferential orientation is evident with mussel valves pointing towards the exterior of the sock and umbos towards the center.
fallax has more robust basidiomata, the pileus is larger (30-40 mm diam.) and with a mammilate central umbo, rhizomorphs are absent, basidiospores are amygdaliform to ellipsoid and larger (6.5-8 x 4-6.5 [mu]m), the pileipellis is a loosely entangled layer of ascending cylindrical hyphae (Baroni, 1981).