Very elongated nuclei near A = 194

A γ-ray cascade in 191Hg of 12 members with average energy spacing 37 keV and Qt= 18(3)eb was reported by Moore and co-workers in 1989. This was the first report of very elongated nuclei (superdeformation) in this mass region. Since then, some 25 γ-ray cascades have been observed in 11 (slightly neutron deficient) Hg, Pb and Tl nuclei. Our collaboration has investigated 7 of these nuclei. The bands have similar dynamic moments-of-inertia. Some nuclei exhibit multiple bands, and the backbending phenomenon has been observed. Level spins can be obtained from comparison of transition energies to rotational model formulas. Selected bands (in different nuclei) have equal transition energies (within 0.1%). Alignment in integer multiples of has been observed. Properties of these bands will be described.