Radio absorption records obtained in or near the zone of totality at two solar eclipses (May 30, 1965 and July 20, 1963) have been examined in detail. It is concluded that all major radio absorption changes during an eclipse are ionization controlled and occur in the D-E layer. Corrections for the ultraviolet sensitivity of the region below 150 kilometers have been applied, so the results indicate effects attributable to the X-ray flux alone. The residual curves clearly show a 'threshold' effect similar to that described by Rastogi et al. (1956) and later by Schmidt and Sharp (1965). Arguments are presented for interpreting this effect in terms of limb configurations involving small, hot X-ray sources similar to that described previously (Meisel, 1968). Once again it is necessary to postulate that grazing incidence reflections from the lunar limb occur. Source positions have been derived from intersections of lunar arcs as seen from different geographic locations.
So far, a total of five sources have been identified with reasonable certainty for three eclipses. All the source positions fall within the zones of maximum coronal X-ray intensity predicted by Elwert (1961). Except for one source located very close to the solar limb, all have positions which are well correlated with optical plages. Wien temperatures have been derived from the lunar reflection trends. These show a pronounced correlation with the relative strengths of the 2 5303 (FexIv) and 2 6374 (Fex) corona near the source locations. Only the strongest and highest temperature sources correlate well with coronal white light structure.