  Non-spherical emulsion droplets can be stabilized by densely packed colloidal
particles adsorbed at their surface. In order to understand the microstructure
of these surface packings, the ordering of hard spheres on ellipsoidal surfaces
is determined through large scale computer simulations. Defects in the packing
are shown generically to occur most often in regions of strong curvature;
however, the relationship between defects and curvature is nontrivial, and the
distribution of defects shows secondary maxima for ellipsoids of sufficiently
high aspect ratio. As with packings on spherical surfaces, additional defects
beyond those required by topology are observed as chains or 'scars'. The
transition point, however, is found to be softened by the anisotropic curvature
which also partially orients the scars. A rich library of symmetric
commensurate packings are identified for low particle number. We verify
experimentally that ellipsoidal droplets of varying aspect ratio can be
arrested by surface-adsorbed colloids.
