— (1) The length varies from about 0.7 to 1.1 mm.
— (2) The shells are transparent, with a light brownish hue. They are decorated with darker brown colour bands. Both the intensity and the width of these colour bands are very variable, but otherwise these bands are a constant character. They end at some distance from the aperture. There is a light, often whitish spot at the apex.
— (3) Ornamental sculpture is completely absent.
— (4) The shells are not very solid. There is no labial rib, nor does the aperture show any other peculiarities.
— (5) Large specimens have about 3.6 whorls.
— (6) There is a narrow and deep umbilicus.
— (7) The dimensions of the apex vary: d = 0.09-0.12 mm, D = 0.16-0.18 mm.
— (8) Seen from aside in position 1, the nucleus is little prominent, and circum¬scribed by a shallow suture. Seen from aside in position 2, the nucleus and first 14 whorl form a medium high segment of a sphere, circumscribed by a rather shallow suture.
— (9) At a magnification of 40 x , no ornamental sculpture can be seen on the protoconch.

A minute conical shell of 3-4 swollen whorls with a blunt tip, the only orna¬ment irregular growth lines; whorls of spire with two spiral brown bands, last whorl with three; aperture nearly circular. The shell is markedly cyrtoconoid in profile; the sutures are deep; the last whorl is much broader than the older ones. Growth lines and the outer lip are prosocline and there is a well-marked umbilicus. 1mm high and 0.8 mm broad; last whorl occupies 65-70% of shell height, aperture 40%.
The body of the animal shows most of the features of rissoid species but has neither pallial tentacle nor penis. A broad metapodial tentacle, however, projects backwards from under the operculum. The flesh is cream with numer¬ous opaque white speckles.
C. fulgida is to be found in low rock pools, where it lives mainly on the bottom in silt or weeds; it often climbs on mucous threads or hangs from the surface film. The snails are detritivores and may be abundant in summer. They have been recorded from most southern parts of the British Isles except the eastern Channel, and from the west coast of Scotland and round Ireland, but are largely absent from the North Sea. Abroad the species ranges south to the Mediterranean.
Breeding (Plymouth, Fretter & Patil, 1961) occurs in spring and summer when colourless, rather large eggs (150 µm across) are enclosed singly in lens-shaped capsules fastened to coralline algae. A free larval stage is missing and the young emerge from the capsules as small snails.

Washed ashore regularly along the North Sea, along the Atlantic coasts of Europe, and in the entire Mediterranean; Canary Islands.