Annals of the South African Museum: Annale Van Die Suid-Afrikaanse MuseumWest, Newman & Company for the trustees of the Museum, 1990 - Natural history |
From inside the book
Results 1-2 of 2
Page 25
... distinguished from Rutitrigonia by its subtrapezoidal outline , with subterminal umbones , almost straight posterodorsal margin and obliquely truncate siphonal margin . In addition , the shell is fastigiate postero- dorsally , due to ...
... distinguished from Rutitrigonia by its subtrapezoidal outline , with subterminal umbones , almost straight posterodorsal margin and obliquely truncate siphonal margin . In addition , the shell is fastigiate postero- dorsally , due to ...
Page 26
... distinguished from the area only in the nepionic stages when it is ornamented . Marginal and inner carinae are lacking , but an umbonal ridge marks the position of the marginal carina . The broad subtrigonal area is weakly concave ...
... distinguished from the area only in the nepionic stages when it is ornamented . Marginal and inner carinae are lacking , but an umbonal ridge marks the position of the marginal carina . The broad subtrigonal area is weakly concave ...
Other editions - View all
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