Description. — Shell very small and fragile, almost transparent. Protoconch with a diameter of about 200 µm, beginning with a nucleus apparently similar to the other species. Teleoconch with up to 4-4,5 convex whorls; the first whorl is sculptured by growth lines crossed peripherally by spiral striae. In the subsequent whorls the microsculpture consists of numerous axial lines which on the upper 15-20% of the whorl are opisthocyrt, while below the shelf they are prosocyrt . On the lower part of the whorl these growth lines are crossed by very fine spiral furrows: about 15 on the first whorl, about 17 on the second, 18 on the last whorl down to the end of the suture and a total of about 30 down to the base in the complete last whorl. Aperture rounded, forming a narrow umbilical slit with the last whorl. Dimensions: Holotype 1.3 mm high.
Distribution. — So far only known from the type locality.
Etymology. — The specific name refers to the country where the species has been collected.
Remarks. — This species can be distinguished from other Atlantic species by the following characteristics.
Murchisonella africana spec. nov. has a smaller number of spiral furrows; the protoconch is smaller; the teleoconch has more convex whorls which increase rapidly in size and the upper part of the whorls is wider (about 30%) while the teleoconch is very short in M. angolensis spec, nov.
Murchisonella saotomensis spec. nov. has a smaller protoconch, the subsutural part of the whorls is larger, and the sculpture is formed by cordlets instead spiral furrow.