Brachiopod Morphology and Genera: (recent and Tertiary) |
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Common terms and phrases
adductor Anomia anteriorly Argyrotheca Atremata beak Beecher Blochmann Bouchardia brachial brachiopods Buckman calcareous cardinal margin cardinal process cardinalia characters chitinous cirri Crania crural bases Cryptopora Dall Dallina Dallininæ Davidson delthyrium deltidial plates deltidium dental plates descending branches Discina Discinisca dorsal valve dorsal view Eocene fathoms Fischer and Oehlert folding foramen fossil genera genotype genus Geol growth Gryphus Hemithyris hinge-line hinge-plates Hinge-teeth hypothyrid interior of dorsal Lacazella lamellæ Laqueus larvæ lateral Lingula Lingula anatina Liothyrella loop loop-development lophophore Macandrevia Magadina Magasella Magellania Magellaniinæ mantle mantle-lobes median septum Megathyris Megerlia Miocene Mühlfeldtia muscles Muscular impressions N.Z. Inst Pachymagas palintrope pedicle pedicle-collar pedicle-opening Platidia plectolophus Pliocene posterior margin posteriorly Proc protegulum Protremata punctate Recent rectimarginate Rhynchonella Schuchert septum setæ shell side socket-ridges species specimens spicules stage subfamily sulcate Tate Telotremata Terebratula Tertiary Thomson Trans transverse umbo uniplicate ventral valve Waldheimia Zealand Zool
Popular passages
Page 171 - In each line of progression the acceleration of the period of reproduction, by the influence of environment, threw off genera which did not go through the complete series of metamorphoses, but are otherwise fully adult, and even may show reversional tendencies due to old age ; so that nearly every stage passed through by the higher genera has a fixed representative in a lower genus. Moreover, the lower genera are not merely equivalent to or in exact parallelism with the early stages of the higher,...
Page 131 - Lower valve with a small septum as in Discina, behind which is an impressed disk or area, externally concave, and internally elevated. This is perforated by a longitudinal fissure, extending from a short distance behind the septum nearly to the posterior margin, which is often slightly indented behind it. Shell more or less horny in texture, minutely tubulous.
Page 319 - Pliocene and Pleistocene Fossils from the Arctic Coast of Alaska and the Auriferous Beaches of Nome, Norton Sound, Alaska.
Page 4 - Protegulum semi-circular or semi-elliptical; hinge-line straight or slightly arcuate. Growth taking place mainly around the anterior and lateral margins, never enclosing or surrounding the pedicle, which in all stages emerges freely between the two valves, the opening being more or less shared by both.
Page 109 - Brachiopoda, with the pedicle opening shared by both valves in nepionic and early neauic stages, usually confined to one valve in later stages, and becoming more or less modified by deltidial plates in ephebic stages. Brachia supported by calcareous crura, loops, or spiralia. Prodeltidium absent. Superfamily RHYNCHONELLACEA Schuchert, 1896.
Page 241 - As a man of science his confreres on both sides of the Atlantic, and on both sides of the...
Page 11 - ... circulation being entirely due to ciliary action. Mr. Morse also described some of the habits of Lingula. While partially buried in the sand the anterior border of the pallial membranes contract in such a way as to leave three large oval openings, one in the center and one on each side.
Page 109 - Types of this order are Orthisina, Strophomena, Producing, Orthis, Pentnmerus, etc. The Telotremata are distinguished in that the "pedicle opening [is] shared by both valves in nepionic stages, usually confined to one valve in later stages, and becoming more or less limited by two deltidial plates in ephebolic stages.
Page 172 - Dallininœ have small cardinal processes, and the interior of the dorsal beak is usually grooved to the apex, while in Magellaniinse there is a well-developed projecting cardinal process often filling the cavity of the beak. The lower genera can be readily determined by the characters of the loop and by the median septum, which is generally low in the Dallininse and projecting above the loop in the Magellaniinse. With these considerations in mind, the metamorphoses and relations of the northern Terebratellidœ...
Page 128 - Neural valve provided internally with two sharp, narrow, incurved laminae, diverging from the beak and extending about one-third the length of the shell ; anterior extremities of the laminae about midway between the mesial line and the margin. Haemal valve with a mesial septum of about the same length extending forward from the beak. Anterior adductor impressions rounded, separated by a faint mesial ridge, faintly impressed. Scar of the post adductor close in the cavity of the beak, rounded. No other...