. Annual report of the Regents. New York State Museum; Science. M'! W%^ Fig. 15. a, A transverse section of a recent species of RKTEroRA, taken parallel to the noncellu liferous surface of the frond, enlarged ; showing the thickened tubes p, to which the avicularia were attached ; h, A section of Coscinium {Coscinotrypa) cribriformis, from the Devonian rocks of Canada, showing similar thickened tubes; c, A section of Rhombopora {Ceriopora) Hamiltonensis, showing similar tubes (after Nicfiolson). The following discussion is from Hiscks' " British Marine Poly- zoa, Yol. I. Introduction, pp.
. Annual report of the Regents. New York State Museum; Science. M'! W%^ Fig. 15. a, A transverse section of a recent species of RKTEroRA, taken parallel to the noncellu liferous surface of the frond, enlarged ; showing the thickened tubes p, to which the avicularia were attached ; h, A section of Coscinium {Coscinotrypa) cribriformis, from the Devonian rocks of Canada, showing similar thickened tubes; c, A section of Rhombopora {Ceriopora) Hamiltonensis, showing similar tubes (after Nicfiolson). The following discussion is from Hiscks' " British Marine Poly- zoa, Yol. I. Introduction, pp. Ixiv-lxxxiii, inc., ; " MoDIFiOATIONS OF THE ZoGEOIAL TyPE. " The structural type of which the zooecium is the most famil- iar representative, exhibits a number of modifications amongst the marine Poltz >a. Of these the most remarkable are the avicularium and vibraculum. These curious appendages are confined to a single saborder, the Cheilostomata, within the limits of which they occur in great abundance and variety. The vibraculum (probably a derivative from the avicularium) is rarely met with as compared with the latter, which is present in a large proportion of the Cheilostomatous genera. The avicu- larium is best known in its most highly specialized form as it occurs in the genera B^gula and Bicellaeia. " This is the true ' bird's head,' an articulated appendage at- tached to the zooecium, with a formidable hooked beak and a mandible worked by powerful muscles, perpetually snapping its jaws with a monotonous energy, and swaying to and fro with a. 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 New York State Museum; University of the State of New York. Board of Regents. Albany : J. B. Lyon, State Printer
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Keywords: ., bookauthorne, bookcentury1800, bookdecade1880, booksubjectscience
