This .NET class wraps the AcDbBody ObjectARX class. 

The Body class is used to represent non-manifold solids and other ShapeManager entities that do not fit the characteristics of the 3dSolid or Region classes.

Autodesk.AutoCAD.DatabaseServices.DBObject
    Autodesk.AutoCAD.DatabaseServices.Entity
        Autodesk.AutoCAD.DatabaseServices.Body

Public Class Body
Inherits Entity

public class Body : Entity;

Region, Solid3d