The selection of N. gibbosulus in Mediterranean websites and N. kraussianus is South African sites is usually a purpose of their availability within the vicinity from the websites, but doesn't describe why this genus was desired above other shells of similar dimension and shape. A comparison of the morphological traits https://medium.com/@spoilmevintagediy/the-rich-history-of-beadwork-a-journey-through-the-ages-4e4fd2e474cf