Shells of Acrosphaera cyrtodon were obtained from core samples collected from the central Indian Ocean Basin (-1010.032 South, 7520.328 East) at a water depth of 5,300 m. The shells were recovered from 20 cm core depth (Core AAS-176b) and prepared for light microscopic observation as a permanent mounted slide. Photomicrographs were made using a binocular microscope and photographed at 200 x magnification. All measurements of shell diameters and pore sizes were made with a Leica microscope and graduated reticule at 250x magnification.
Living colonial radiolaria were collected by SCUBA divers using hand-held polycarbonate jars to enclose the organisms as they drifted past or by plankton sampling using gentle net tows (1 mm mesh, 1 m diameter nets) according to previously published techniques (Anderson et al. 1991, Anderson 1992). The samples were collected at a location approximately 10 km southwest of Castle Harbour Bermuda during July, 1997. Living colonial radiolaria were observed and photographed with a dissecting microscope using dark field illumination.