\begin{table}%t3
\caption{\label{t3}Synoptic table containing the main results concerning the 4 
X-ray binaries (see Fig.~\ref{f4}) identified or observed in the present sample 
of {\it INTEGRAL} sources.}
\par
%\centerline
{
\begin{tabular}{lccccccccccr}
\hline
\hline
\multicolumn{1}{c}{Object} & \multicolumn{2}{c}{H$_\alpha$} & 
\multicolumn{2}{c}{H$_\beta$} &
\multicolumn{2}{c}{He {\sc ii} $\lambda$4686} &
Optical & $A_V$ & $d$ & Spectral & \multicolumn{1}{c}{$L_{\rm X}$} \\
\cline{2-7}
 & $EW$ & Flux & $EW$ & Flux & $EW$ & Flux & mag. & (mag) & (kpc) & type & \\
\hline
IGR J11435$-$6109 & 25.8 $\pm$ 1.3 & 39 $\pm$ 2 & 3.5 $\pm$ 1.1 & 2.2 $\pm$ 0.7 & $<$2.2 & $<$1.2 &
16.43$^{\rm a}$ ($V$) & 5.7 & $\sim$8.6 & B2~III & 2.5 (0.16--3.5) \\
& & & & & & & & & & or B0~V & 8.2 (0.3--10) \\
& & & & & & & & & & & 16 (20--100) \\
%& & & & & & & & & & & \\ 
1ES 1210$-$646 & in abs. & in abs. & in abs. & in abs. & 2.8 $\pm$ 0.3 & 21 $\pm$ 2 &
13.9 ($R$) & 3.3 & $\sim$2.8 & B5~V & 1.9 (0.16--3.5) \\
& & & & & & & & & & & 64 (1--8) \\
& & & & & & & & & & & 12 (2--10) \\
& & & & & & & & & & & 1.0 (20--100) \\
%& & & & & & & & & & & \\ 
IGR J17404$-$3655 & 14.2 $\pm$ 0.14 & 2.5 $\pm$ 0.3 & $<$9 & $<$0.9 & $<$6 & $<$0.6 &
17.3 ($R$) & 3.1 & $\sim$9.1 & --- & 12 (2--10) \\
& & & & & & & & & & & 13 (20--100) \\
%& & & & & & & & & & & \\ 
IGR J21347+4737 & 8.1 $\pm$ 0.6 & 5.1 $\pm$ 0.4 & 1.2 $\pm$ 0.2 & 1.2 $\pm$ 0.2 & 1.6 $\pm$ 0.4 & 1.7 $\pm$ 0.4 &
14.2 ($R$) & 2.2 & $\sim$5.8 & B3~V & 0.08 (0.5--8) \\
& & & & & & & & & & & 6.0 (20--100) \\
\hline
\end{tabular}}
\par
\medskip
Note: $EW$s are expressed in \AA, line fluxes are in units of 10$^{-15}$ erg cm$^{-2}$ s$^{-1}$, whereas X-ray luminosities are in units of 10$^{34}$ erg s$^{-1}$ and the reference 
band (between brackets) is expressed in keV. \\
$^{\rm a}$ From Negueruela et~al. (\cite{Negueruela07}).
\end{table}