39 pairs of galaxies have been observed (Ref. 1–4 and references herein). They are listed in Table 1. They can be classed in two categories. For 23 of them, one component has a compact stellar-like nucleus (Byurakan classes 4 and 5) and the other component has a faint nucleus of undefined form (Class 2) or no nucleus (Class 1); for one pair in this category, one component has a compact nucleus and the other belongs to Class 3. The components of the 16 other pairs have similar nuclei, compact or not. Out of the 39 pairs 6 have one component with a complex nucleus (Subclass 2s), the other component having a compact or non-compact nucleus.