One can tessellate 4-dimensional Euclidean space by regular 16-cells. Five space-filling polyhedra can tessellate 3-dimensional euclidean space using translations only. The "endo-dodecahedron" is concave and equilateral; it can tessellate space with the convex regular dodecahedron. The regular enneagon can tessellate the euclidean tiling with gaps. In contrast, regular pentagons do not tessellate. It is possible to tessellate in non-Euclidean geometries such as hyperbolic geometry. The rhombic dodecahedron can be used to tessellate three-dimensional space. Infinite forms tessellate a one-lower-dimensional Euclidean space. Like the rhombic dodecahedron itself, this shape can be used to tessellate three-dimensional space. This polytope can tessellate Euclidean 6-space, forming the 2 honeycomb with this Coxeter-Dynkin diagram&colon; . It can tessellate space to form the disphenoid tetrahedral honeycomb. The truncated cuboctahedron can tessellate with the octagonal prism. The regular octadecagon can tessellate the plane with concave hexagonal gaps. Cuboids are among those solids that can tessellate 3-dimensional space. Infinite forms can be extended to tessellate a hyperbolic space.