Iphitus marshalli: This unique species has been found off Portugal and the Straits of Gibraltar. It is a tiny species reaching a maximum size of about 2.5mm and has been taken in depths ranging from 530 to 2000m. It appears to have over 100 thin thread-like costae per whorl. 4-5 raised spiral ridges are present on each of the 3 teleoconch whorls. There are 4 protoconch whorls, the center two of which are ribbed. The oval aperture is very large relative to the size of the shell, with up to 8 spiny projections on the outer lip.