A small conical shell with flat-sided profile and without obvious ornament; apical whorls usually reddish brown, younger whorls of spire with pale adapical and reddish brown abapical halves; last whorl also with basal brown spiral. Operculum crimson with silvery refringence. Animal without pallial and meta-podial tentacles. The shell has five whorls, slightly swollen, the last sometimes slightly keeled at the periphery, and all smooth except for microscopic growth lines. The aperture is oval, pointed apically, has no varix, and there may be a small spout at the base of the columella. There is no umbilicus. The protoconch is rather globular and has a finely pitted surface. Up to 2 mm high, 1.5 mm broad; last whorl occupies 70% of shell height, aperture 40%. The body of the animal shows much the same external features as those of any rissoid. It is yellowish, with many dark lines, and there is a bright yellow spot by each eye, The opercular lobes are black.
B. unifasciata is a southern species not found further north than the British Isles, where it is widespread except for the southern parts of the North Sea and the Channel east of the Isle of Wight. It is to be found on algae, mainly fine red weeds, and in pools near low water mark, on rocky shores, often in abundance in summer. It feeds on algae and epiphytic diatoms.
The animals breed in spring and summer, laying spherical capsules with thick walls on weeds, often on coralline algae. The capsules have a diameter of 500-600 µm and contain only a single, rather large egg. This hatches as a juvenile. Information on the biology and ecology of this species is given by Southgate(1982).

Perhaps this species is better known under the name of Barleeia rubra that however is a preoccupied name, so not to be used.
Shell solid, conic in outline, suture linear but evident, whorls either flat-sided or not much convex. Protoconch paucispiral and it presents a regular spiral microsculpture made by very little folds. Aperture oval in form, external lip simple, rarely it presents varices, columella arched, umbilicus missing. Periphery convex and non sharp-cornered. Surface smooth and bright. Colour is variable: usually uniform brown reddish in colour but it often presents one streak, below-suture and at the base of last whorl, dirty white in colour. Operculum corneous dark brown in colour. It is recognizable from B. gougeti since this last one is larger in sizes, it is stronger, it has a periphery much more sharp-cornered and it is uniform white yellowish in colour constantly. In literature there are quoted some varieties in colour such as: pallida, albescens, but also some varieties in form such as variety elongata B.D.D. reaching 4.5 mm in height. Average measures of adult specimens are around 3 mm in height.

Habitat: it lives on algae, on rocky bottoms. It feeds on detritus and diatoms, in the mesolittoral and infralittoral zones. Distribution: it can be found all over the Mediterranean. Quite common.