Page:Scientific results HMS Challenger vol 18 part 1.djvu/871

Synopsis of the Genera of Tholonida.

III. Subfamily Amphitholida. Cupolas developed only in the direction of one single axis (commonly two cupolas). (Tholonida unidimensiva.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Central chamber simple, without medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Two simple cupolas (without veil),	289. Tholartus.
				Two double cupolas (with veil),	290. Tholodes.
		Central chamber Larnacilla-shaped, with enclosed medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Two simple cupolas (without veil),	291. Amphitholus.
				Two double cupolas (with veil),	292. Amphitholonium.
III. Subfamily Staurotholida. Cupolas developed in the direction of two axes perpendicular one to another (commonly four cupolas). (Tholonida bidimensiva.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Central chamber simple, without medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Four simple cupolas (without veil),	293. Tholostaurus.
				Four double cupolas (with veil),	294. Tholoma.
		Central chamber Larnacilla-shaped, with enclosed medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	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.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Central chamber simple, without medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Six simple cupolas (without veil),	297. Tholocubus.
				Six double cupolas (with veil),	298. Tholonium.
		Central chamber Larnacilla-shaped, with enclosed medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	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).

1. Tholartus = Cupola-bread; θόλος, ἄρτος.