Ancylus fluviatilis

Ancylus fluviatilis is a species of very small, freshwater, air-breathing limpet, an aquatic pulmonate gastropod mollusk in the tribe Ancylini within the family Planorbidae, the ram's horn snails and their allies. The 5–8 mm.limpet-like shell has a backwardly directed, conical apex. The shell shape is higher than Acroloxus and Ferrissia.The apex is blunt when seen from above,but appears more pointed from the side. The shell is bent backwards and very weakly to the right side. It is thin and translucent, with reticulate sculpture and fine growth lines.In colour it is light yellowish to reddish brown or dull pale brown. The animal is grey with black dots near the head and almost entirely covered by the shell. The tentacles are triangular with eyes at their base. The genital pore and pneumostome are very small and located at the right side.