\begin{table}%T4
%\centering
\small
\caption{Origin of optical counterparts to XMM sources.} 
\label{tab:fors} 
\begin{tabular}{lrr}\hline\hline 
\multicolumn{2}{l}{Obtained optical spectra for X-ray sources} & 
207\\\hline 
\multicolumn{2}{l}{Positive literature classifications by Marano} & \\ 
\multicolumn{2}{l}{et~al. (1988) and \cite{zitelli} (partly reobserved)} & 30\\\hline 
\multicolumn{2}{l}{New optical counterparts of ROSAT sources} &  \\ 
\multicolumn{2}{l}{\cite{zamorani} (partly reobserved)} & 14 \\\hline 
\multicolumn{2}{l}{New positive spectroscopic classifications of XMM sources} & 96\\\hline 
\multicolumn{2}{l}{Total positive spectroscopic classifications of XMM sources} & 140\\\hline 
\end{tabular} 
\end{table}