THE mathematical problem of the seismological implications of aeolotrophy in continental structure has been discussed by Robert Stoneley (Mon. Not. Roy. Astro Soc., Geophysical Supplement, 5, No. 8, 343 ; 1949). He finds that for near earthquakes, erronemous values of the focal depth and thickness of layer might be found from the observations if the continental material had been thought to be isotropic. Further, for a transversely isotropic continent, SH waves would travel with a different velocity from that of S V, and the law of variation of velocity with direction would be different. With body waves, the sharp distinction into compressional and distortional waves would not hold, and an explosion would generate an S wave as well as a P wave ; an apparent difference in the instant of generation of P and S might arise. Stoneley has also proved that waves of the Rayleigh type can be propagated over the surface of a transversely isotropic body in which the axis of circular symmetry is normal to the free surface, supposed plane ; in such waves the diminution of amplitude with depth is shown to be different from that in an isotropic body, so that the amplitudes of the surface waves generated by a source at a given depth will be different from that which they would be in an isotropic medium. Love waves can be propagated as in isotropic media. Byerly noted a possible double refraction effect on the crust of the earth for waves from the earthquake of July 6, 1934 (Butt. Seism. Soc. Amer., 28, 12 ; 1938). Miss I. Lehmann may also have noted a similar effect (Pub. Bur. Cent. Seism. Int., A, No. 12, 109 ; 1935).