The wall is made up of typically “rounded-rectangular” truncated spicules arranged irregularly. The test begins with a very low-convex trochospiral stage of about 10 chambers, arranged in 2 coils, with oblique sutures. In this stage chambers increase slowly in size. Chambers of the second stage become rapidly elongate-crescent. They are added irregularly and the last ones may have lengths of about one third of the circumference of the chambered test. They are subdivided by secondary septa. The last stage is represented by an irregularly contoured flange, containing randomly dispersed spicules embedded within fine agglutinated particles. The first stage and part of the second stage of the test are dark brown in color. The end of the second stage and the flange are yellowish or white.