Page:Scientific results HMS Challenger vol 18 part 2.djvu/674

The Central Capsule of the Cannorrhaphida seems to possess the same shape in the three subfamilies, and to agree in general with that of the Aulacanthida. In a living specimen of Dictyocha stapedia, which I observed at Ceylon (Pl. 101, fig. 10), the three openings of the Tripylea were distinct; the radiate operculum of the astropyle (on the oral pole) was surrounded by the granules of the dark phæodium, whilst on the opposite aboral side, two parapylæ or conical secondary openings were visible. The voluminous spherical calymma (about four times as broad as the central capsule) contained numerous large alveoles (as in Aulosphæra) and its surface was protected by numerous pileated pieces of the skeleton; the basal ring of the latter was placed tangentially in the spherical surface of the calymma, their apical spine being directed outwards. The pseudopodia, arising from the central capsule and forming a network between the alveoles of the calymma, radiated outwards in great number from its surface (Pl. 101, fig. 10).

The propagation by self-division seems to be very frequent in the Cannorrhaphida. I frequently found two equal central capsules in one calymma, as in the first observed species, Cannobelos cavispicula, and in Cannorrhaphis spinulosa (Pl. 101, fig. 3), sometimes also in Dictyocha and Distephanus. As already mentioned, Catinulus constantly exhibited four central capsules united in each calymma.

Synopsis of the Genera of Cannorrhaphida.

I. Subfamily Cannobelida. Pieces of the skeleton cylindrical or spindle-shaped tangential tubules.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Tubules simple, smooth,			658. Cannobelos.
		Tubules spiny or branched,			659. Cannorrhaphis.
II. Subfamily Catinulida. Pieces of the skeleton hemispherical or cap-shaped, solid.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Caps or hemispherical pieces of the skeleton solid, with radiate margin and circular opening,			660. Catinulus.
III. Subfamily Dictyochida. Pieces of the skeleton either simple rings or pileated or pyramidal bodies, composed of thin hollow rods and reticular meshes.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Flinty pieces simple or arched rings, not truncated pyramids, with a basal ring, but without apical ring.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Basal ring simple, not arched or fenestrated,	661. Mesocena.
				Basal ring fenestrated, with two or more arches, vaulted over one side,	662. Dictyocha.
		Flinty pieces of the skeleton resembling a truncated pyramid, with an upper smaller apical ring, and a lower larger basal ring.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Apical ring simple, not fenestrated (one girdle of meshes on each piece),	663. Distephanus.
				Apical ring fenestrated (two girdles of meshes on each piece),	664. Cannopilus.