Shell conical with anterior margin of aperture marked by a slit continued to apex as groove. Apex curving posteriorly to end about three quarters of total length behind the anterior end. nearly level with highest point of shell. Surface reticulated by ridges. White. Animal with about twenty epipodial tentacles.
A minute spiral coil of two whorls lies on the right posterior side of the apex. There are 25-35 radial ridges crossed by 20-30 others parallel to the edge of the aperture or to its previous positions. These are narrower than the radial ridges and are clearest between them. There are small knobs where the two sets cross. The aperture is oval, its edge made sinuous by the ends of the ridges. Up to 10 mm long, 8 mm broad. 6 mm high.
The animal has a broad snout and two rather thick tentacles, each with an eye on a short stalk on its outer side; the right cephalic tentacle has an epipodial tentacle immediately behind it. The mantle skirt is split under the slit in the shell and extends a little through it to form an exhalant siphon. The sole of the foot is oval; there is no operculum; the median epipodial tentacle posteriorly is longer than the others. Flesh white.

E. fissura is a sponge eater and is not uncommon on rocky coasts to about 150m sublittorally and at L.W.S.T., usually on the underside of large stones supporting sponge growths and with a pitted surface in which the limpets rest. They avoid brackish water. They occur on all suitable shores in the British Isles except the east Channel and the southern North Sea. The species is found on all European Atlantic coasts.