diff --git a/EGkSurfTriMesh.h b/EGkSurfTriMesh.h
index 41056b6..72323e2 100644
--- a/EGkSurfTriMesh.h
+++ b/EGkSurfTriMesh.h
@@ -124,9 +124,12 @@ class __declspec( novtable) ISurfTriMesh : public ISurf
       virtual bool Repair( double dMaxEdgeLen = MAX_EDGE_LEN_STD) = 0 ;
       virtual bool GetAllTriaOverlapBox( const BBox3d& b3Box, INTVECTOR& vT) const = 0 ;
       virtual const BBox3d& GetAllTriaBox( void) const = 0 ;
-      virtual int  GetPartCount( void) const = 0 ;
+      virtual int GetPartCount( void) const = 0 ;
+      virtual int GetShellCount( void) const = 0 ;
       virtual bool RemovePart( int nPart) = 0 ;
+      virtual bool RemoveShell( int nShell) = 0 ;
       virtual ISurfTriMesh* ClonePart( int nPart) const = 0 ;
+      virtual ISurfTriMesh* CloneShell( int nShell) const = 0 ;
       virtual bool SetTFlag( int nId, int nTFlag) = 0 ;
       virtual bool GetTFlag( int nId, int& nFlag) const = 0 ;
       virtual int  GetMaxTFlag( void) const = 0 ;