Annals of the South African Museum: Annale Van Die Suid-Afrikaanse MuseumWest, Newman & Company for the trustees of the Museum, 1990 - Natural history |
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Page 25
... Broad subtrigonal area essentially flat , meeting the posterodorsal commissure in an acute angle , so that the shell is fastigiate ( roof - shaped ) posteriorly . Ornament comprises coarse , robust , relatively sparse costae that are ...
... Broad subtrigonal area essentially flat , meeting the posterodorsal commissure in an acute angle , so that the shell is fastigiate ( roof - shaped ) posteriorly . Ornament comprises coarse , robust , relatively sparse costae that are ...
Page 26
... broad , weakly curved anterior margin is subvertical and curves evenly into the long , almost straight , ventral margin . The broad , obliquely truncate respiratory margin meets the straight posterodorsal margin in a very obtuse angle ...
... broad , weakly curved anterior margin is subvertical and curves evenly into the long , almost straight , ventral margin . The broad , obliquely truncate respiratory margin meets the straight posterodorsal margin in a very obtuse angle ...
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Common terms and phrases
abbreviated according to chronology acute angle Aitken ANNALS antecarinal sulcus bicuspidata Gould Broad subtrigonal area Cape Town comma separates comprises coarse concentric costae curve strongly upwards described Haughton escutcheon fastigiate roof-shaped flank costae Gastropoda GENUS OF RUTITRIGONIINAE Hoepen holotype Kobayashi krenkeli Lamarck Lange Later flank Leda LOWER CRETACEOUS APTIAN margin and obliquely marginal carina Megatrigonia middle growth stages Nakano namacolus nepionic stages noteworthy similarities Nucula obliquely truncate opisthogyrous beaks ornament comprises paratypes parentheses posterodorsal commissure punctuation reduction or enlargement references registration number respiratory margin ribbing Roman numerals RUTITRIGONIINAE BIVALVIA scientific name separate author's name shell is fastigiate Shell medium sized shouldered italics Smith South African Museum species straight posterodorsal margin strongly upwards posteriorly subconcentric subheadings are shouldered subterminal umbones subtrapezoidal Synonymy arrangement Syrotrigonia taxa Trigonia Rutitrigonia TRIGONIACEA umbonal ridge V-shaped costae ventral margin VOLUME 99 volume number Von Huene weakly ZULULAND Zulutrigonia gen Zulutrigonia pongolensis Rennie