from above

Description:

Portrait of Pyxidicula, a small testate amoeba in the family Arcellidae. This is an optical section through he cell center. The nucleus can be seen at 8 o clock just above a contractile vacuole. The chitinoid test has an inverted bowl shape with a broad pseudostome that is nearly the diameter of the test. The surface of the test is pitted with small puncta. Among filamentous algae in freshwater pond near Boise, Idaho. Differential interference contrast.