Observations of 855 Shapley-Ames galaxies made during the period 1980 November 1-1988 October 31, together with improved supernova luminosities, have been used to derive the frequency of supernovae of differing types. For an average Shapley-Ames galaxy we find the following supernova rates: SN Ia (0.28 +/- 0.10)h^2^ SNU, SN Ib (0.27 +/- 0.15)h^2^ SNU, and SN Il (1.04 +/- 0.30)h^2^ SNU, in which 1 SNU is defined as one supernova per 10^10^L_B_(sun) per 100 yr. These rates are similar to those derived in our previous paper.
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Evans et al. (1989) studied this question.
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