Evidence for new isotopes of element 107: 266Bh and 267Bh

New neutron rich isotopes, 267Bh and 266Bh, were produced in bombardments of a 249Bk target with 117-MeV and 123-MeV 22Ne ions at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Identification was made by observation of correlated alpha-particle decays between the Bh isotopes and their Ha and Lr daughters using a rotating wheel system. 267Bh was produced with a cross-section of about 70 pb and decays with a 17+14-6 s half-life by emission of alpha particles with an average energy of 8.83(plus or minus)0.03 MeV. One atom of 266Bh was observed, decaying within one second by emission of a 9.29-MeV alpha particle.