The secondary chamberlets in the original description of Cushman and Edwards 1937 that give the stellate appearance were noted by Tappan as resulting from non-porous flaps that project backwards from each chamber partly covering the preceding suture and umbilical region but leaving a small open cavity beneath, giving the appearance of secondary chamberlets.
12.
The regions are the left and right hypochondriac regions, so named because they lie under the ribs; the epigastric region which is approximately where the stomach is located between the hypochondriac regions; the right and left lumbar regions which flank the umbilical region ( which surrounds the umbilicus, or belly button ), the right and left iliac / inguinal regions which are where the hips are, and the hypogastric / pubic region, which lies between the hips.
