Strobilops aenea is one of my favorite snails. They are tiny—the shell of this individual was 2.3 mm across—with prominently ribbed dark brown shells.
The coloration of the body is not unique to this genus. There are species in other genera with a similar dichotomous color pattern: dark upper surface with dark tentacles and white sides and tail.
But the conical shape of the shell is characteristic of Strobilops aenea and most of the other species in the genus. I don't know of any other North American land snail genus with a similar shell shape.
And now for something completely different: