Basic properties (normalized distributions) of the H i sample (N = 312 galaxies, blue dashed line), the H i refined subsample (N = 166 galaxies, blue solid line), as well as the optically complete sample (Verdes-Montenegro et al. 2005, red dash-dotted line): a) velocity (V[km s^-1]); b) morphology (T(RC3), as in the RC3 catalog); c) optical luminosity (log(L_B[L_⊙])); and d) FIR luminosity (log(L_FIR[L_⊙])).