Plectomerus dombeyanus shell description:

 “Shell long rhomboid, subinflated to inflated, solid, inequilateral; beaks only moderately full and high, their sculpture consisting of a few decidedly nodulous corrugations; posterior ridge strong and high, often pinched up into a sharp angle, ending at the base of the shell in a point; anterior end a little narrowed and rounded; base line straight; post-dorsal area somewhat winged; posterior end obliquely truncated with a slightly curved outline; surface with a few oblique folds in front of the posterior ridge and on the posterior end there are curved folds; umbonal region with lengthened nodules arranged in zigzagged patterns; epidermis brownish or blackish; pseudocardinals ragged, radially split; laterals long; muscle scar large, the anterior ones filled with roughened nacre; beak cavities moderately deep; pallial line remote; nacre purple-red ”(Simpson, 2014; Mather, 2007).