  This brief report (6 pages) was written in 1983 but never published. It
concerns the hyperbolic 3-orbifolds obtained as quotients of hyperbolic 3-space
by the group of invertible 2 by 2 matrices whose entries are integers in the
imaginary quadratic extension of Q of discriminant D. For values D > -100 the
topological type of this orbifold is tabulated, and in the cases when the
topological type is a punctured 3-sphere, the singular locus of the orbifold is
drawn. A few miscellaneous comments about these orbifolds are included. The
tables and pictures are based on Bob Riley's computer calculations of Ford
domains and face pairings. Nothing is said about later developments after 1983.
The pictures are also viewable on my webpage in a perhaps more convenient
format; see http://math.cornell.edu/~hatcher
