kpc.

These two samples are used in the present investigation to derive frequency distributions which need to be extracted from a magnitude complete sample (Sects. 5.3-5.4). The remaining objects observed in this work and/or found in the literature will be used only in those analysis which do not depend upon completeness (Sect. 5.1, 5.2). We remark that, since the studied galaxies belong to a structure (the Coma supercluster) approximately at constant distance from the observer, a volume limited sample can be easily extracted from the present magnitude complete sample.

Table 1 lists the observed galaxies as follows:

Col. 1: CGCG designation (Zwicky et al. 1961-1968). Col. 2-3: NGC/IC, UGC (Nilson 1973) names. Col. 4 and 5: 1950 celestial coordinates (1-2 arcsec uncertainty). Col. 6 and 7: major and minor axes (in arcmin) as determined at the 25 (see Gavazzi & Boselli 1996). Col. 8: heliocentric velocity from the literature. Col. 9: cluster membership (see Gavazzi & Boselli 1996 for more details). Members of Coma and A1367 are those objects with a projected angular separation within 2 and 1 degrees respectively from their X-ray centers. One galaxy belongs to the N4794 group, another to the N3937 group in the foreground of 