Annals of the South African Museum: Annale Van Die Suid-Afrikaanse Museum

abbreviated Abstract according acute angle adult Aitken allied ANNALS antecarinal sulcus appear arrangement author's name authors bicuspidata BIVALVIA broad Cape Town capital caption chronological cited coarse collected comma commissure concentric consecutively COOPER curve described DESCRIPTION designated Diagnosis distinguished escutcheon FEBRUARY figures flank costae flat follow forms genus give given Haughton headings holotype illustrations included indicated initial italics journal Kobayashi krenkeli Lange Leda letters locality Lycett marginal carina marked material medium sized meeting Megatrigonia MICHAEL Nakano nepionic stages Note obliquely truncate original ornament ornament comprises paratypes parentheses pongolensis Rennie posteriorly published punctuation reduction references ribbing robust scientific name separates shell shell is fastigiate shouldered Smith South African Museum species specimen straight posterodorsal margin strongly upwards subheadings subterminal umbones subtrapezoidal subtrigonal Synonymy taxa Trigonia Rutitrigonia TRIGONIACEA Type umbonal ridge ventral margin volume weaken weakly Zulutrigonia gen