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The sheath of dura mater which covers the spinal cord.
A moss capsule.
A pollen sac.
The layer of stroma surrounding a Graafian follicle.
(invertebrate zoology)
The test of a testate protozoan or a rotifer.



various types of sheath in animals and plants:

(1) A cell wall in certain amoebae (thecamoebae).

(2) A chitinoid membrane in hydroid polyps; hence the division into the suborders Thecaphora and Athecata.

(3) The connective tissue surrounding ovarian follicles in vertebrates (theca folliculi).

(4) A tooth socket in the jawbone of mammals and crocodiles.

(5) A capsule for spores in mosses.

(6) The valve of a silicified test; in diatoms, the upper half is the epitheca and the lower half, the hypotheca.

(7) The pollen sac of an anther in angiosperms.

References in periodicals archive ?
Gothograptus nassa has the largest number of thecae of any species of the Gothograptus lineage, up to 18 pairs.
Neogothograptus alatiformis Lenz & Kozlowska-Dawidziuk, 2004 is the smallest form of this genus with only three thecae and a well-developed, dense reticulum, especially in mature colonies.
1 and 2)that dominates the floral display while 5-6 stamens are fertile and produce thecae containing pollen.
The apical appendages are neither constricted nor demarcated from the thecae, as commonly occurs in the subfamily Asteroideae, except in Adenocaulon and Eriachaenium (Fig.
Each anther consists of two equivalent halves, the thecae, joined together and with the filament by a connective.
Corolline corona often present as small lobes in throat or ridges behind anthers; anthers sometimes with short, sterile apical appendages (Diplorhynchus, Dyera) or with short sterile appendages at apex and thecae bases (Pycnobotrya); leaves opposite or whorled; plants of the Old World Melodineae
The anther thecae can be separated by a broad connective or confluent, symmetric or asymmetric, and be parallel or divergent to various degrees at maturity.