/usr/include/dolfin/generation/ is in libdolfin-dev 2016.2.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dolfin/generation/BoxMesh.h
/usr/include/dolfin/generation/IntervalMesh.h
/usr/include/dolfin/generation/RectangleMesh.h
/usr/include/dolfin/generation/SphericalShellMesh.h
/usr/include/dolfin/generation/UnitCubeMesh.h
/usr/include/dolfin/generation/UnitDiscMesh.h
/usr/include/dolfin/generation/UnitHexMesh.h
/usr/include/dolfin/generation/UnitIntervalMesh.h
/usr/include/dolfin/generation/UnitQuadMesh.h
/usr/include/dolfin/generation/UnitSquareMesh.h
/usr/include/dolfin/generation/UnitTetrahedronMesh.h
/usr/include/dolfin/generation/UnitTriangleMesh.h
/usr/include/dolfin/generation/dolfin_generation.h