Description. — Shell small, almost cylindrical, very fragile and transparent. Protoconch with about one whorl, with the typical shape of the genus, a nucleus of about 30 µm and a diameter between 150-180 µm. The teleoconch has up to 6 whorls with very slowly increasing diameter, the profile is rather uniformly convex, suture distinct. It is not possible to observe any separation of the upper and lower parts of each whorl. The microsculpture is formed by about 10-15 irregular furrows that are more prominent in the upper l/3 rd of the whorl, crossed by opisthocyrt growth lines which are more convex on the adapical part of the whorl. Aperture rounded. A narrow umbilical furrow is present. Dimensions: the holotype is 1.4 mm in height. Other specimens examined are smaller.
Distribution. — So far only known from New Caledonia.
Etymology. — The name alludes to the fine spiral striae typical for the species.
Remarks. — Some shells are wider but show no difference in the other characteristics and are therefore considered an intraspecific variation.
The most similar species are P. planicula spec. nov. and P. indivisa spec, nov., but both these species have a clear spiral sculpture formed by ovate, spirally aligned pits.
For comparisons with other species of Pseudoaclisina see further below.