\begin{table}%t4
%\centering
\par
 \caption{Summary  of  the  optical  properties  of  the  sources  at
$0.4<z<0.6$  observed with HST and  results of our  study on the
images.  Note that  only one source of our  sample (classified as HEG)
has  no HST  data available  (\object{3C~327.1}).  \object{3C~275} has
also been excluded because of a cosmic ray event in the central region
of the HST image (see text, Sect.\ref{sez:hstobs}).}\label{t4}
\begin{tabular}{lccccc} 
\hline\hline  {}& CCC detections & Optical upper  limits  & Complex morphology 
& TOT  & \% CCC detections\\  
\hline 
BLO& $8$ & $-$ & $-$ & $8$  & $100\%$\\ 
LEG& $1$ & $3$ & $1$  & $5$  & $20\%$\\  
HEG&  $3$ & $6$  & $4$  & $13$  & $21\%$\\
\hline
{\bf All sources} & $12$ & $9$ & $5$ & $26$ & $44\%$\\
\hline 
\end{tabular} 
\end{table}