During the past decade much effort has been spent also on observation and theoretical modelling of AGB stars. However, the Semiregulars have been almost neglected. Kerschbaum & Hron (1992) used GCVS- and IRAS-data to define samples of SRa and SRb stars. These were compared with optical Miras with respect to their pulsational properties, effective temperatures, mass loss rates, luminosities, scale heights and galactic volume densities.