Pustulosa nodulata shell description:

“Shell subquadrate, inflated, slightly inequilateral, solid; beaks high and full, turned forward over a lunule, their sculpture a few coarse, irregular corrugations; posterior ridge well developed, narrowly rounded or subangular, sometimes inclined to be double below; anterior end rounded, sometimes feebly angled above; base line slightly curved; posterior end almost squarely truncated, sinused in the middle at the termination of a radial depression above the posterior ridge; surface with a few large warts or pustules, often arranged in two imperfect rows, one on the posterior ridge, the other some distance in front of it; epidermis generally smooth, subshining, ashy-green in young shells, rarely feebly rayed, ashy-brown in old shells; pseudocardinals considerably split up; lateral of the right valve single or double; beak cavities deep, compressed; anterior scars small, deep; nacre white, iridescent behind”(Simpson, 2014; Mather, 2007).