\begin{table}%T2
\caption{Column densities$^{\rm a}$  and $b$ values for the IVC and HVC towards Sk~-68~80.}\label{tab2}
%\centerline
{
\begin{tabular}{lrrrr}
\hline
\hline
Species & log $N_{\rm IVC}$ & $b_{\rm IVC}$ & log $N_{\rm HVC}$ & $b_{\rm HVC}$ \\
        &                   & [km~s$^{-1}$] &                 & [km~s$^{-1}$] \\
\hline
C~{\sc i}   &  $\leq $13.4 & $\rm 5.9^{+2.9}_{-1.3}$ & $\leq 12.4$ & $\rm 30.0^{+9.2}_{-5.4}$ \\ 
O~{\sc i}   &  $14.8\pm0.1$ &                    & $14.8\pm0.1$ & \\
Si~{\sc ii} &  $14.3\pm0.2$ &                    & $13.8\pm0.1$ & \\
P~{\sc ii}  &  $12.8\pm0.1$ &                    & $\leq 12.3$ & \\
Ar~{\sc i}  &  $12.9\pm0.1$ &                    & $\leq 12.6$ & \\
Fe~{\sc ii} &  $14.1\pm0.1$ &                    & $14.0\pm0.1$ & \\
\hline
H$_2$~$J=0$ & $\rm 16.5^{+0.1}_{-0.5}$ & $\rm 1.5^{+0.8}_{-0.2}$ & $\leq 15.6$ & $\geq 1$ \\
H$_2$~$J=1$ & $\rm 16.0^{+0.3}_{-0.5}$ &                     & $\leq 15.1$ & \\
H$_2$~$J=2$ & $\rm 14.4^{+0.3}_{-0.2}$ &                     & $\leq 14.2$ & \\
H$_2$~$J=3$ & $\rm 14.6^{+0.3}_{-0.2}$ &                     & $\leq 15.3$ & \\
H$_2$~$J=4$ & $\rm 13.7^{+0.1}_{-0.1}$ &                     & $\leq 14.2$ & \\
H$_2$~total & $\rm 16.6^{+0.5}_{-0.5}$ &                     & $\leq 15.6$ & \\
\hline
\end{tabular}}
\par
\smallskip
$^{\rm a}$ Column densities, $1\sigma$ errors and $3\sigma$
upper limits are given.
\end{table}