Caseolus sphaerulys is a species of small land snail, a terrestrial pulmonate gastropod mollusk.

In Latin,"sphaerula" is a noun meaning "little sphere", so it does not change ending.

This species of land snail lives in Madeira on dry, stony ground.

This species is threatened by forest replanting, mixed forms of pollution, erosion and the impact of improved access to its habitat.

Its future prospects are bad and the species is likely to become extinct in its biogeographical region.