. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Stromatoporoids and of Eozoon. 440 systems alroody in existence. The formation of a new lamina is due to the buddin^? upwards from an original central or '' interpolated central " cliamber, the bud becoming the centre of a new spiral. The peripheral series of chambers may become C3'clical. In Orhitolites there is often a change from a spiral to a cyclical plan. The small central chamber has a narrow straight neck, whence originates the circumambient chamber, and the latte
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Stromatoporoids and of Eozoon. 440 systems alroody in existence. The formation of a new lamina is due to the buddin^? upwards from an original central or '' interpolated central " cliamber, the bud becoming the centre of a new spiral. The peripheral series of chambers may become C3'clical. In Orhitolites there is often a change from a spiral to a cyclical plan. The small central chamber has a narrow straight neck, whence originates the circumambient chamber, and the latter continues the spiral and gives off radial offshoots. The sarcode following the circumambient chamber becomes seg- mented, owing to the formation of radial \ertical partitions, and the outer walls increase in thickness. Fio-. Clathrodictyon striatellum, d'Orb. Wenlock. chamber, x 30. a, interpolated central A var} ing degree of complexity is brought about by the pressure of neighbouring spiral systems on each other and by the curving of successive laminae. Each lamina represents so many vertically produced buds^ each with its system of spirals^ and each latilaniina marks a season of growth. A vertical section of an Actl7iostromac\\i%i\\\ou^\\ so many coils, each coil being in relation to a central chamber. Some- times a central chamber produces a wart or tubercle. The branched forms {Idiostroma^ Stachyodes) have only vertical budding along one 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 original London, Taylor and Francis, Ltd
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Keywords: ., bookce, booksubjectbotany, booksubjectgeology, booksubjectzoology
