This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.

Higher levels: rads_cat -> O -> Orbula -> Orbula ducalis
Other pages this level: O. comitata, O. discipulus, O. ducalis

Orbula ducalis

Citation: Orbula ducalis Foreman 1973
Rank: species
Type specimens: pl.3, fig.12, pl.10, figs.11,12
Type repository: Holotype n°USNM 178757, DSDP 10- 86-8(CC), S19/0; paratype n°USNM 178758, DSDP 10-86-8(CC), M35/3 U.S. National Museum, Washington, D.C.
Described on page(s) : p.438
Family (traditional): Theoperidae
Family (modern): Bekomidae

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Current identification/main database link: Orbula ducalis Foreman 1973

Original Description
Cephalis subspherical in lateral view, subtriangular in transverse section, with corners of triangle truncate coinciding with position of vertical and secondary lateral bars which protrude as tiny thorns. Apical horn may be small, thorn-like, or larger and cylindrical. Cephalis and proximal thorax poreless, minutely papillate. Cephalis pitted apically, distally frequently nodose. Internally the collar stricture has six collar pores as in 0. comitata. Externally the collar stricture not distinct as the contour of the cephalis merges with that of the thorax. Thorax with two distinct flaring expansions, the distalmost much broader than the first; subtriangular in transverse section. Aperture constricted, subtriangular, surrounded by a rounded rim with surface minutely papillate. Three ribs extend from the collar stricture and terminate in three short feet at the point where the thorax constricts. Thoracic pores subcircular, arranged quincuncially in vertical rows, gradually increasing in size to the point of greatest expansion; surface tuberculate.

(Based on twenty specimens) Length of cephalis and thorax 100-150µm; greatest width of thorax 190-245µm, of aperture 120-160µm. Distinguishing characters (rw): This species is distinguished from 0. comitata and 0. discipulus as described under those species.


Foreman, H. P. (1973a). Radiolaria of Leg 10 with systematics and ranges for the families Amphipyndacidae, Artostrobiidae, and Theoperidae. Initial Reports of the Deep Sea Drilling Project. 10: 407-474. gs


Orbula ducalis compiled by the radiolaria@mikrotax project team viewed: 26-10-2020

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