Menetus dilatatus

Menetus dilatatus is a species of small air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Shell description.
The shell is small, of a yellowish green-color, minutely wrinkled by the lines of growth. The spire is flat, composed of 2.5-3 whorls, separated by a well-defined suture. The outer whorl has a sharp margin on a level with the spire, diminishing near, but still modifying, the aperture. Below this line the whorl is very convexly rounded so as to encircle a small, deep, abruptly formed umbilicus. This whorl rapidly enlarges, and terminates in a very large, not very oblique aperture, with the lip expanded so as to make it trumpet-shaped.
The width of the shell is 2–3 mm. The height of the shell is 0.9 mm.
Distribution.
The species is native to North America. The type locality is Nantucket island and Hingham, Massachusetts, USA.
Its non-native distribution includes:
Habitat.
This snail lives in freshwater biotopes.
References.
This article incorporates public domain text from the reference.