Abstract
Four species of Cymatium (Turritriton) have very similar spiral sculpture, the primary cords each bearing three high, narrow riblets. The earliest is C. domingense (Gabb) from late early Miocene to early Pliocene rocks of the Dominican Republic. The other three species seem likely to be descended from C. domingense, and either have no fossil record, or are known as fossils only from the late Pliocene or Pleistocene. C. labiosum (Wood) occurs now in the Indo-West Pacific, the western Atlantic, and (rarely) West Africa; C. gibbosum (Broderip) in the Panamic province of tropical western America; and C. kobelti (von Maltzan) in West Africa, and newly recorded from the western Mediterranean Sea. C. gibbosum and C. kobelti are closely similar si ster species, differing by little other than protoconch shape and coloration.