Synopsis of the Genera of Tholonida.
Cupolas developed only in the direction of one single axis (commonly two cupolas). (Tholonida unidimensiva.) |
I. Subfamily Amphitholida.
Central chamber simple, without medullary shell. | Two simple cupolas (without veil), | 289. Tholartus. | ||
Two double cupolas (with veil), | 290. Tholodes. | ||||
Central chamber Larnacilla-shaped, with enclosed medullary shell. | Two simple cupolas (without veil), | 291. Amphitholus. | |||
Two double cupolas (with veil), | 292. Amphitholonium. | ||||
Cupolas developed in the direction of two axes perpendicular one to another (commonly four cupolas). (Tholonida bidimensiva.) |
II. Subfamily Staurotholida.
Central chamber simple, without medullary shell. | Four simple cupolas (without veil), | 293. Tholostaurus. | ||
Four double cupolas (with veil), | 294. Tholoma. | ||||
Central chamber Larnacilla-shaped, with enclosed medullary shell. | Four simple cupolas (without veil), | 295. Staurotholus. | |||
Four double cupolas (with veil), | 296. Staurotholonium. | ||||
III. Subfamily Cubotholida.
Cupolas developed in the direction of three axes perpendicular one to another (commonly six cupolas). (Tholonida tridimensiva.) |
Central chamber simple, without medullary shell. | Six simple cupolas (without veil), | 297. Tholocubus. | ||
Six double cupolas (with veil), | 298. Tholonium. | ||||
Central chamber Larnacilla-shaped, with enclosed medullary shell. | Six simple cupolas (without veil, | 299. Cubotholus. | |||
Six double cupolas (with veil), | 300. Cubotholonium. |
Subfamily 1. Amphitholida, Haeckel.
Definition.—Tholonida with monaxial growth; cupolas opposite on the poles of one axis. (Shell commonly three-chambered, with two domes on both sides of the central chamber.)
Genus 289. Tholartus,[1] n. gen.
Definition.—Tholonida with simple cortical shell (without external veil); with two hemispherical cupolas, opposite on the poles of one axis; central chamber between them simple (without medullary shell).
- ↑ Tholartus = Cupola-bread; θόλος, ἄρτος.