Figure 27: Canaliferous spines in Baculogypsina sphaerulata (
A-B: Epoxy resin casts of shell cavities, the mineralized shell having been dissolved, showing that spine canals originate as extensions of an intraseptal interlocular space, that is then transformed into canals. They feed in their turn the supplemental chamberlets overgrowing the base of the spine. C-D: Shell showing chessboard pattern of supplemental chamberlets, overgrowing the base of the canalled spine and fed in part by the overgrown canal orifices.
a: aperture (of lateral chamberlet); co: canal orifice; csp: canalicular spine; lcl: lateral chamberlet; lh: loop-hole; nep: (spiral) nepiont; sp(c): spine canals; st: stolon.