Lapideacassis mariae Black, 1971b
Tall species of Lapideacassis having the ratio of height to the width [without spines and collar] is greater than 2.0. No spine was noted. The second distal tier is tapering in holotype but in our material, it is parallel-sided.
Lapideacassis mariae is easily distinguished from another non-spine bearing species Lapideacassis glans by being tall. The height/width ratio [without spines and collar] is less than 1.5 in the latter species. The specimens illustrated here are similar to Lapideacassis trispina by having parallel-sided second distal tier but differs from it by lacking any spines.
Black, M., 1971b. Problematical Microfossils from the Gault Clay. Geological Magazine 108(4), 325-327.
Gault near Mildenhall, Suffolk, England.