. Bulletins of American paleontology. Molts from Shubuta Clay, Mississippi 63 PREVIOUS WORK Kesling (1951, 1952, 1953) presented many of the problems associated with species recognition of instars. Several ontogenetic studies have been made (for example, Spjeldnaes, 1951; Martinsson, 1957, 1962; Hartmann, 1961; Sandberg, 1964; Sohn and Anderson, 1964). These and other papers have discussed the ontogeny of valve outline, surface ornamentation, hingement, muscle scars, marginal features, and normal pore canals; however, most papers utilizing data on immature instars have been biometrical in natu
. Bulletins of American paleontology. Molts from Shubuta Clay, Mississippi 63 PREVIOUS WORK Kesling (1951, 1952, 1953) presented many of the problems associated with species recognition of instars. Several ontogenetic studies have been made (for example, Spjeldnaes, 1951; Martinsson, 1957, 1962; Hartmann, 1961; Sandberg, 1964; Sohn and Anderson, 1964). These and other papers have discussed the ontogeny of valve outline, surface ornamentation, hingement, muscle scars, marginal features, and normal pore canals; however, most papers utilizing data on immature instars have been biometrical in nature. Fowler (1909) used the work of Brooks (1886) in determining growth factors for living ostracodes and stated that each stage increased by a fixed percentage of its length approximately constant for its species and sex. This statement he named "Brook's ; In spite of Fowler's growth factors ranging from to , Przibram (1931) used a growth factor of for all arthro- pods assuming that mass is doubled at each molt, being the cube root of COMPOSITE STRATIGRAPHIC COLUMN EASTERN MISSISSIPPI RED BLUFF. 5" CLAYSTONE LEDGE; FERRUGINOUS 3' CLAY;IV10STLY CALCAREOUS; QUARTZ SILTY; FERRUGINOUS; GYPSIFEROUS 9' CLAY;MOSTLY CALCAREOUS; GYPSIFEROUS 32' CLAY; MOSTLY CALCAREOUS PACHUTA 15' CLAY; MOSTLY CALCAREOUS; QUARTZ SILTYs SLIGHTLY FERRUGINOUS; CORALS CLAY; MOSTLY CALCAREOUS "—TI— 12' CLAY; MOSTLY CALCAREOUS; GLAUCONITIC 5' MOSTLY COVERED 6' MARLY LEDGE; QUARTZ SANDY TO SILTY; GLAUCONITIC; MACROFOSSILIFEROUS Text-figure 2. Composite measured section of the Shubuta Clay deter- mined from localities near Shubuta, Mississippi. Arrows point to sampled horizons, the lowermost arrow corresponding to an elevation of 175 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 Paleonto
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Keywords: ., bookauthorpaleonto, bookcentury1800, bookdecade1890, bookyear1895
