flux from the galaxy might be slightly underestimated accordingly.

224004S: no redshift is available for this object, thus the filters adopted for 224004 could not match the $\rm H\alpha$ line. The $\rm H\alpha$ flux should be considered a lower limit.

224038: this peculiar object in A2197 might be the remnant of a galaxy collision. The complex velocity field in this galaxy was studied by Maehara et al. (1988).

Analysis
========

To complement our imaging survey, we use in the following analysis $\rm H\alpha$ data taken from the literature. Table 4 summarizes the data in the Cancer and Virgo clusters and in the Coma supercluster regions.

Col. 1: CGCG designation (Zwicky et al. 1961-1968). Col. 2-3: NGC/IC, UGC names. Col. 4, 5: $\rm H\alpha$ equivalent width, along with its error and source reference.

The Dependence of the SFR on Hubble Type and Mass
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In this section we use the $\rm H\alpha$ E.W. reported in Tables 3 and 4 in order to study the relationship between the current star formation and other photometric properties of disk galaxies. First we show in Fig. 5a the relation between the $\rm H\alpha$ E.W. and the morphological type. The Hubble classification is represented by discrete 