The Zeeman effect of the intrinsic Sn${\mathrm{O}}_{2}$ exciton (direct forbidden) has been measured at 1.8\ifmmode^\circ\else\textdegree\fi{}K, thus facilitating the identification as well as the interpretation of the anisotropic exciton spectra. The exciton symmetries and possible band symmetries are obtained on the basis of group theory and appear to be consistent with the valence band of O $2p$ functions and the conduction band of Sn $5s$ functions, both being crystal field split.