using the Kolmogorov-Smirnov test (the probability that the cluster and isolated distributions derive from the same parent population is 2.5 %). This indicates, contrary to common believe, that cluster spiral+Irr galaxies have mean SFR values indistinguishable from those of the isolated objects. The histograms in Fig. 9 b and c suggest, however, that the cluster sample has a less pronounced peak at Log $\rm H\alpha$ E.W. = 1.4 than the isolated one. Conversely there is a marginal evidence for an overabundance of intermediate $\rm H\alpha$ E.W. (0-10 $\rm \AA$) among cluster objects. However, based upon the data in our possession, these differences are not statistically significant.

It is well known that late-type galaxies avoid the central regions of rich clusters. This is clearly the case in the Coma cluster (see Andreon 1996), and to a lesser extent in A1367. It has been claimed that spirals at the periphery of the Coma cluster have bluer than average color indices. Donas et al. 1995, for example, find an enhancement of objects with blue UV-B excess. If this reflects an enhanced SFR, it is expected that a similar pattern should show up in our data. The radial distributions of the $\rm H\alpha$ E.W. 