The phase transitions in a few members of homologous series of 4,4’-dialkylbiphenyls were reinvestigated. The new orthogonal smectic phase existing between the smectic E and the smectic S-Bcryst. phase was found in these compounds. The existence of a different smectic E phase in the same compounds was confirmed by thermomicroscopic, roentgenographic and DSC studies. Measured and calculated lattice spacings in E, E’ and B phases are given.