Microscopic shells in seafloor sediment collected from Blake Ridge. The large, round shell at the top left of the image is a planktonic pteropod about 0.25mm across. The triangular shell immediately underneath is a benthic, or bottom dwelling, foraminifer, Bolivina. All other larger shells, including the pink one (Gloobigerinoides), are planktonic foraminifers. The planktonic shells have fallen from the surface waters to the seafloor. Image courtesy of Deep East 2001, NOAA/OER.
