Geiger, D. L. The Nautilus 120: 45-51.
Sasakiconcha elegantissima, a new genus and species from the Western Pacific is described. The specimens are most similar to members of Anatomidae (Anatoma, Thieleella) with a peripheral selenizone, but close the slit to a foramen, and lack a columella because of a disjointly coiled base resulting in an umbilical trough. Additionally, an aberrant specimen of Scissurella morretesi Montouchet, 1972, which shows repeated closure of the slit to form foramina, is discussed with respect to the evolutionary pathway from the ancestral open slit to its modification as a single or a series of foramina.
Pdf files of many publications are available here.