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It is known that the SA is not complete to its stated magnitude limit of mpg = 13m.2 but becomes progressively more incomplete as this magnitude level is approached. A study of the incompleteness (Sandage, Tammann, and Yahil, 1979) suggests that the fraction f(m) of a complete sample in fact contained in the SA is well represented by

f (m) = [e(m-12.72) / 0.19 + 1]-1,

where m is the magnitude in the BT system.

In this representation, the progressive incompleteness of the SA is a rapid function of m, as shown in figure 6 of the above-stated reference, where the equation is compared with counts of E and S0 galaxies contained in fainter catalogs. Note that at m = 12m, f (m) = 1, while at m appeq 12m.7, f (m) is only 0.5.

As an aid toward the eventual revision of the SA to a more complete magnitude-limited catalog, we list in Appendix A those galaxies that should be included to a limit of BT appeq 13m.2, obtained by converting the magnitudes in the Nilson and the Zwicky catalogs to the BT system. In Appendix B, we list particular dwarf galaxies (many of which are well known) that should also be included. These lists are of course incomplete, if only because they are predominantly for the northern hemisphere. It should also be cautioned that the types and magnitudes of these candidate galaxies are more uncertain than those in the main table.