. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. Science. 54 [Assembly Phyllogkaptus ttpus in two extreme forms. A', A', Y. 1 1. — I- ?"^. Under this genus are described : Phyllogra'ptus typus, P. ilicifolius, P. angustifolius, and P. similis. While these discoveries have been made in Canada, giving us for the first time a correct knowledge of the mode of growth and the varying forms of these bodies, I have not neglected opportunities of increasi
. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. Science. 54 [Assembly Phyllogkaptus ttpus in two extreme forms. A', A', Y. 1 1. — I- ?"^. Under this genus are described : Phyllogra'ptus typus, P. ilicifolius, P. angustifolius, and P. similis. While these discoveries have been made in Canada, giving us for the first time a correct knowledge of the mode of growth and the varying forms of these bodies, I have not neglected opportunities of increasing our knowledge of these fossils from localities within my reach. The locality of graptolites near Albany has heretofore fur- nished several species, which, now that we know better their original forms, offer additional information, and become of greater interest both in their zoological and geological relations. At this locality, some specimens have been obtained which show apparently the mode of reproduction in this family of animals, which is more similar to the hydroid polyps than to the Bryozoa*. The specimens in which this fieature has been observed, first show a slight swelling or vesicle proceeding from the axils of the serra- tures : this vesicle, which in the beginning is barely perceptible beyond the outlines of the margin, swells and becomes elongated, the extremity finally much inflated, and the base of the footstalk extended and attenuate. As this process of development goes on, the sac or inflated portion curves downwards, and finally becomes ruptured or dehiscent on the lower side near the extremity. At this period, and sometimes previously, the sac, which appears to be an extremely thin membrane and almost without substance, shows one or two elongated fibres, like the central midrib or the marginal longitudinal fibre of the graptolites. At a more advanced stage the * This notice was read at the meeting of the American Association for the Advance- ment of Sci
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectscience, bookyear1853
