\begin{table}%t3
\caption{\label{tab3}Photometry of selected extended sources.}
%\centerline
{
\begin{tabular}{lcllccl}
\hline\hline
Source & Size    &  TDT &     Filter & Integrated      &  Correction & Integrated \\   
       & (arcmin)&      &            & Flux Density         &  Factor     & Flux Density\\
       &         &      &            &(ISOPHOT; Jy)    &             & (IRAS; Jy)$^{a}$\\
\hline
NGC~6946&  $9 \times   7$  & 05302402 &   C60  &  $111.5 \pm  6.5$  &   1.45      &     146.5\\
NGC~6946&         & 05302401 &   C200 &  $365.8 \pm 11.7$  &   1.11      &        --\\
M~51$^{b}$   &  $9\times   6$  & 17200618 &   C60  & $ 70.3 \pm  3.0$  &   1.30      &       84.9\\
M~51$^{b}$   &         & 17200618 &   C100 & $162.2 \pm 12.3$  &   1.33      &      192.6\\
M~51$^{b}$   &         & 17200820 &   C160 & $180.9 \pm 23.9$  &   1.07      &        --\\
M~101   & $21 \times   10$ & 16500615 &   C60  &   $61.1 \pm  3.2$  &   1.15      &       92.9\\
M~101   &         & 16500716 &   C100 &  $204.5 \pm 10.2$  &   1.12      &      263.5\\
M~101   &         & 16500716 &   C160 &  $360.5 \pm 49.0$  &   1.06      &        --\\
\hline
\end{tabular}}
\smallskip
$^{a}$  From Table~4 of Rice et~al. (\cite{Rice1988}).\\
$^{b}$ Together with companion galaxy NGC 5195.\\
\end{table}