Thesis (Ph. D.)--University of Chicago, 1908. / "Reprinted from the Journal of geology, vol. XVII, no. 1, Jan.-Feb., 1909." Includes bibliographical references.

Thesis (Ph.D.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: David J. Varricchio. Includes bibliographical references (leaves 148-166).

Thesis (M.S.)--Ohio State University, 1974. / Includes bibliographical references (leaves 50-55). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, March 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 417-434)

No description available.

The presence of spicule pseudomorphs and an aquiferous filtration system in Mesozoic stromatoporoids confirms poriferan affinity for this previously problematic group. The form, and postulated original siliceous nature of most of the spicules, indicates that the possessors of these were calcified demosponges; others with originally calcareous spicules were calcareans. Different spicule types and arrangements indicate that the possession of a calcareous skeleton is a convergent feature. Previous defining characteristics are found to be invalid and Mesozoic stromatoporoids are redefined as calcified sponges, so that the term 'stromatoporoid' now only refers to a grade of organisation of the calcareous skeleton and not a taxonomic grouping. 'Chaetetids', 'sphinctozoans' and 'sclerosponges' are also polyphyletic groupings, representing grades, where some members of which are calcified demosponges. These groupings should no longer be considered in isolation, as this has previously obscured their true nature. The original mineralogy of late Mesozoic stromatoporoids was probably low-Mg. calcite. Spicule and calcareous skeleton diagenetic lineages are given to enable workers to determine original microstructures. Analogies with Recent calcified demosponges, suggests that the fossil stromatoporoid demosponges produced a primary framework of siliceous spicules bound together with an organic matrix, which probably provided the nucleation sites for subsequent precipitation of the calcareous skeleton. A new taxonomic scheme is presented based on spicule type, arrangement and relationship of this framework to the microstructure of the calcareous skeleton. On the basis of spicule criteria, calcareous microstructure alone is found to be convergent and can no longer be used as a high-level taxonomic feature. Spiculate species are therefore redescribed and placed within the Recent poriferan classification framework. Synonyms are documented and intra-specific variation discussed. The present cnidarian-based nomenclature is replaced by one modified from Recent poriferan terminology. The possession of a calcareous skeleton is probably a relict feature of a previously widespread calcified sponge fauna. It appears that the calcareous skeleton was acquired independently in a number of lineages in the early Palaeozoic, and has subsequently been lost in many.

No description available.

The main purpose of this study is to reconstruct the Post Glacial vegetational and climatic changes indicated by the pollen grains and spores preserved in the Camosun peat bog. Utilizing this knowledge an attempt is made to define the approximate age of the earliest microfossil deposits of this bog by comparison of the results with those of Hansen (1947). A single sample core was taken from the Camosun bog. The core was divided into ten centimetre channel specimens, each of which was macerated using a new technique. The macerated material, including the microfossils were mounted on slides, and percentage frequencies were obtained for the microfossils in each specimen. The frequency results were interpreted and conclusions drawn on the basis of the kind and number of microfossils recovered. It is concluded that the primary forest was composed mainly of Pinus, which changed later into a forest characterized by Pseudotsuga and Tsuga. Thus the climate appears to have changed from warm and dry to cooler and more moist. The approximate age of the first deposits is defined as ranging between four and six thousand years. Finally various suggestions for future work are presented, including proposals for future studies in the same bog, and methods for the improvement of palynological techniques in general. / Science, Faculty of / Botany, Department of / Graduate

No description available.