. The Devonian crinoids of the State of New York. Crinoidea, Fossil; Paleontology; Paleontology. DicLjcltc Monocyclic Figure 28 Diagrams of Dicyclic and Mono- cyclic bases showing the position of the cirri with reference to the plates of the dorsal cup. IB, infrabasal; B, basal; R, radial; ci, cirri; co, pentameres of column; n, nerves going to cirri from extensions of capsule; s, suture between pentameres of column. (After Bather 1898, 1900) exterior angles of the stem are interradial; but the longitudinal sutures, the sides, the lobes of the axial canal and the cirri of the stem are radial;
. The Devonian crinoids of the State of New York. Crinoidea, Fossil; Paleontology; Paleontology. DicLjcltc Monocyclic Figure 28 Diagrams of Dicyclic and Mono- cyclic bases showing the position of the cirri with reference to the plates of the dorsal cup. IB, infrabasal; B, basal; R, radial; ci, cirri; co, pentameres of column; n, nerves going to cirri from extensions of capsule; s, suture between pentameres of column. (After Bather 1898, 1900) exterior angles of the stem are interradial; but the longitudinal sutures, the sides, the lobes of the axial canal and the cirri of the stem are radial; in crinoids with a true monocyclic base the conditions are reversed. This is true only of species with a pentangular or pentapartite stem or canal. Bather points out (1898, p. 423; 1900, p. 106) that this law is liable to excep- tions; and he believes that a surer guide for discriminating between monocyclic and dicy- clic forms is obtained by attending chiefly to the rela- r tion of the axial cords. Figure 29 Relation of cirri to axial cords. A, part of stem The appendages of the of Isocrinus decorus, with cirri in whorls of five. 1 n A ' ' A +V, B, section across stem of Isocrinus wyville- COiumn are Called CIYYI and the thomsoni at level of cirrus-whorl, the central portions ossicles Composing them are disproportionally enlarged for greater clearness. C, section _ . across stem of a fossil crinoid showing branch from axial ClTTdLS. I he C1IT1 are Dome by canal to cirrus. (After Bather, 1900) the nodals and thrQUgh the nodal communicate with the axial canal; they therefore correspond in position with the five axial cords (figures 28, 29). Cirri may be given off 3. 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 Goldring, Winifred, 1888-1971. Albany : University of the State of New York
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpaleont, bookyear1923
