BL Lacertae objects detected in the HEAO-1 all sky X-ray survey

We discuss 20 X-ray sources in the NRL HEAO-1 catalog which we identify with bright, hard X-ray emitting BL Lac objects. We discuss the definition and process of identification of these objects. We deduce limits to the surface density of > 0.0007 deg−2 at fluxes > 1.5 x 10−11 ergs cm−2s−1; although the sample is not completely identified. We present the first quantitative attempt to justify previous empirical statements about differences in polarization and broad band colors between radio-selected vs. X-ray selected objects.