Channeled pebblesnail
The channeled pebblesnail, scientific name Somatogyrus wheeleri, was a species of very small freshwater and brackish water snails that have an operculum, aquatic gastropod mollusks in the family Lithoglyphidae. This species was endemic to Arkansas in the United States. Its natural habitat was the Ouachita River. References

Somatogyrus
Extinct gastropods
Gastropods described in 1915
Taxonomy articles created by Polbot
Endemic fauna of Arkansas