Electron‐Microscopic Observations of Gromia oviformis (Sarcodina).

Abstract

SYNOPSIS. Gromia oviformis from New Zealand has been examined in thin sections after fixing in osmium tetroxide and embedding in methacrylate. The structure of the protein and acid mucopolysaccharide shell and the canals which pass radially through it are described. Multiple honeycomb membranes located between the shell and the cytoplasm, as well as mitochondria and “Golgi bodies,” none of which has hitherto been seen in light microscope studies, are discussed and illustrated. The previously known stercomata and xanthosomes are considered. Though still regarded as enigmatic cytoplasmic inclusions, observations suggest that they are waste products retained within the animal throughout life.

The ultrastructure of a planktonic foraminifer, Globigerinoides sacculifer (Brady), and its symbiotic dinoflagellates

“…Much research has been performed on the cytology and life history of benthic foraminifera (Schaudinn, 1895;Lister, 1903;Myers, 1935;Le Calvez, 1938, 1950Jepps, 1942;Grell, 1957;Hedley and Bertaud, 1962;Angell, 1967Angell, , 1971Lengsfeld, 1969a, b, c), but only a few cytological studies on planktonic foraminifera exist. Rhumbler (191 1) examined the test and cytoplasm of a wide variety of planktonic species.…”

Fine Structure of a Marine Ameba Associated with a Blue‐Green Alga in the Sargasso Sea*,†

“…The average number of merozoites per meront in the 3 generations was 10 (5-15). I4 (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), and 7.5 (6-16) : and the average size was 4.4 x 2.1 (4.1-5.9 x 1.8-2.2) pm, 4.2 x 1.8 (4.0-4.8 x 1.5-2.0) pm: and 5.4 x 1.8 (5.2-7.8 x 1.6-2.0) pm. respectively.…”

A New Allogromiid Foraminifer Niveus Flexilis Nov. Gen., Nov. Sp., From Coastal Georgia, Usa: Fine Structure and Gametogenesis

“…Other taxa, including Myxotheca sp. Sub-plasma membrane vesicles have been reported in the filopod Gromia oviformis (Hedley and Bertaud, 1962;Hedley and Wakefield, 1969), which is a genetically close relative to the Foraminifera based on a variety of genetic markers (Archibald and others, 2003;Berney and Pawlowski, 2003;others, 2003, 2004;Nikolaev and others, 2004), suggesting that this morphology is an ancestral character state. It appears that new test material is transported to the periphery of the cell in various locations by vesicles to allow for an increase in diameter, thus widening the single chamber (Goldstein and Barker, 1988;Goldstein and Richardson, 2002).…”