\begin{table}%t3
\caption{Refined classification of the type~2 sources (both type~I
and type~II), which is based on the emission line ratios computed
from their optical spectra.}\label{tableline}
%\centering
\small
\begin{tabular}{cccc}
\hline \hline
   & Type I 2 & Type II 2 & $N$ \\
  \hline
  \textbf{SF glx} & 16 & 5 & 21 \\
  \textbf{Sy 2} & 5 & 5 & 10 \\
  \textbf{ALG} & 2 & 1 & 3 \\
  \textbf{Undef} & 2 & 2 & 4 \\ 
  \hline
    N & 25  &  13 & \textbf{38} \\
    \hline
\end{tabular}
\end{table}