CLASSIFICATION.
Geometry.
Properties of circles, 873, 875, 877.
Non-Euclidian geometry, 827.
General theory of curves, 820, 832, 868.
Correspondence, 819, 821.
Orthomorphosis, 821, 845.
Plane Quartics, 816.
Groups of points, 880, 883.
General theory of surfaces, 799, 806.
Quadrics, 882.
Quartic surfaces, 817.
Centro-surfaces, 864.
Minimal surfaces, 884.
Rays, 876.
Curves of curvature, 886.
Twisted cubic curves, 838.
Twisted quartic curves, 843, 859.
Miscellaneous, 809, 810, 812, 837, 840, 857.