\begin{table}%T2
      \caption{\label{Tab1}The SDSS DR5 main samples used,  and the FoF parameters
      for the group catalogue (DR4 is for comparison, but not used).}
         \small%\centerline
{
         \begin{tabular}{cccccccccc}
            \hline\hline
            \noalign{\smallskip}
          Sample &  RA,~$ \lambda$ & Dec,~$ \eta$ & $N_{\rm gal}$ &
        $N_{\rm groups}$&$N_{\rm single}$&$LL_{\rm r0}$ & $LL_{\rm p0}$ &
    $ z_* $ & $ a $   \\
    & deg & deg &  & & & km~s$^{-1}$ &  Mpc/h &  & \\
             1 & 2 & 3 & 4  & 5 &
          6 & 7 & 8 & 9 & 10 \\
            \hline
            \noalign{\smallskip}
SDSS DR4 E  & 120\ldots 255 & --1\ldots16     &  116~471  & 16~244  & 65~016 &
250 & 0.25 & 0.138 & 1.46 \\
SDSS DR4 N  & --63\ldots +63  & 6\ldots39 & 197481  & 25~987   & 115~488 &
250 & 0.25 & 0.138 & 1.46 \\
\\
SDSS DR5 E  & 120\ldots 255 & --1\ldots16     &  129~985  & 17~143  &  75~788 &
250 & 0.25 & 0.055 & 0.83 \\
SDSS DR5 N  & --63\ldots +63  & 6\ldots39 & 257~078  & 33~219   & 152~234 &
250 & 0.25 & 0.055 & 0.83 \\
            \hline
         \end{tabular}}
\smallskip Columns:
 1:  Subsample of the SDSS redshift catalogue, 
 2:  right ascension limits for the equatorial (E) sample,  $\lambda$
  coordinate limits for the northern~(N) sample (degrees), 
 3:  declination limits for the E sample,  $\eta$ coordinate limits for
  the N sample (degrees), 
 4:  number of galaxies in a subsample, 
 5:  number of groups in a subsample, 
 6:  number of single galaxies, 
 7:  FoF linking length in radial velocity,  for $z=0$, 
 8:  FoF linking length in the projected distance in the sky,
    for $z=0$, 
 9:   characteristic scaling distance for the linking length,
    see Eq.~(\ref{lz}),  Sect.~5, 
 10:  scaling amplitude for the linking length,  see
  Eq.~(\ref{lz}),  Sect.~5. 
   \end{table}