Description of Arcella aculeata
provided by BioPedia
Spindle-shaped hypotrich ciliate, elongate, with a rounded posterior and long, thin neck region. Body 90 microns long. The peristome extends for one-half the body length. The contractile vacuole is anteriorly located. There are two ovoid macronuclei.
Description of Centropyxis aculeata
provided by BioPedia
Testate amoeba, test discoidal, flat, somewhat beret-shaped; dorsal surface rounded, ventral flat to concave; aperture ventral, may be circular to uneven but displaced towards one end; fine spines present on edge, may be at one end only or all around the periphery; surface smooth, dorsally with many quartz grains and a little cement, ventrally polished-looking due to more cement and much smaller grains in test. Length of shell 92-178 microns, breadth of shell 77-137 microns, depth of shell 40-72 microns and diameter of aperture 31-30 microns.
