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 24
... ribbing of the neanic stage is of such a character in both these species as to exclude them from Indotrigonia in spite of adult similarities , and Rutitrigonia is the only term available for species of Trigonia having features at all ...
... ribbing of the neanic stage is of such a character in both these species as to exclude them from Indotrigonia in spite of adult similarities , and Rutitrigonia is the only term available for species of Trigonia having features at all ...
Page 25
... ribbing weakens or is effaced , and the generally V - shaped costae of the adult . Significantly , however , the V - shaped costae are far from uniformly developed and in some indi- viduals examined they simply bend strongly upwards as ...
... ribbing weakens or is effaced , and the generally V - shaped costae of the adult . Significantly , however , the V - shaped costae are far from uniformly developed and in some indi- viduals examined they simply bend strongly upwards as ...
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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