. Elementary text-book of zoology [electronic resource]. Zoology. GYMNOMYXA. 99 Amceha is a type of the single class Rhizopoda in which there are pseudopodia, and of the order Lobosa, with blunt or lobose pseudopodia, but there are three other important orders to which we may briefly allude. The Heliozoa or sun-animalcules are usually spherical in shape, and are found in freshwater. The pseudopodia are long rays usually stiff- ened with a central rod of silica. The central mass of protoplasm is vacuolated, and some have a hollow perforated shell like the next order. Nearly all are centro-symme
. Elementary text-book of zoology [electronic resource]. Zoology. GYMNOMYXA. 99 Amceha is a type of the single class Rhizopoda in which there are pseudopodia, and of the order Lobosa, with blunt or lobose pseudopodia, but there are three other important orders to which we may briefly allude. The Heliozoa or sun-animalcules are usually spherical in shape, and are found in freshwater. The pseudopodia are long rays usually stiff- ened with a central rod of silica. The central mass of protoplasm is vacuolated, and some have a hollow perforated shell like the next order. Nearly all are centro-symmetric. I'ig- 33-—^ Heliozoan {Adinophrys sol). The entire animal magnified. (^Ad. nat.') Vacuole. Note the central nucleus and stiffened pseudopodia. The second order is that of the Radiolaria. They are marine pelagic organisms of microscopic size and have a siliceous skeleton of isolated pieces called spicules, or a continuous perforated shell through the holes of which the fine radiating pseudopodia protrude. The main mass of protoplasm has a thin capside dividing it into central and peripheral portions, and in the peripheral parts there are often found a number of minute algoid bodies called yellow (ells. They live and multiply in close organic unity with the radiolarian. Such a union is termed sy/iibiosls (see Chapter IX.). Radiolarians are commonly centro-symmetric, but some are axo-symmetric. Countless numbers of them live and die in the pelagic water, and their shells and spicules cover the sea-floor at great depths, constituting radiolarian ooze (Chapter IX.). The third order, Foi-aniiiiifera, also consists of a vast assemblage of small pelagic organisms. They usually have a shell, made of calcareous, arenaceous or chitinous material. It is often chambered,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the
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