Siouan languages
Authors who call the entire family "Siouan" distinguish the two branches as "Western Siouan" and "Eastern Siouan" or as "Siouan-proper" and "Catawban". Others restrict the name "Siouan" to the western branch and use the name "Siouan–Catawban" for the entire family. Generally, however, the name "Siouan" is used without distinction.
Ohio Valley Siouan languages
The Ohio Valley Siouan, or Southeastern Siouan, languages are a subfamily of the Western Siouan languages, far to the east and south of the Mississippi River. The group has Ofo and Biloxi, in the Lower Mississippi River valley, and Tutelo, historically spoken in Virginia, near the territory of the Catawban languages. All of the languages are now extinct.