\begin{table}%t4
\caption{\label{t:hco}\HCOp\ observations. Isotopes are abbreviated as 12~(\HCOp), 13~(H$^{13}$CO$^+$), and 18~(HC$^{18}$O$^+$).}
\par
%\centering
\small
\begin{tabular}{lc@{~}crcccc @{}c@{}c@{}c l}
\hline\hline\noalign{\smallskip}
 & & &\TL, K $^a$ &\multicolumn{2}{c}{${v_{\rm LSR},\mkm}\ ^b$} & {10\% width  $^c$}\  &  
                   Profile & \multicolumn{2}{c}{${\rm Size, arcsec}$}& PA &  \\
source& isotope & line & peak &centroid& abs.&\km & 
              type & $\Delta l$ & $\Delta b$ & deg. &remark  \\
	      \hline
SGRB2MC     & 12 &3--2 &  9.7 &  ?   & 70.6& 67.7 & &&& &complex profile,\\
            & 13 &3--2 &  4.0 & 56.7 & 62.5& 30.7 & R & &&& broad abs. below cont.   \\  
G10.62-0.38 & 12 &3--2 & 21.5 & --5.1 & 0.0 & 18.1   &   &22.8 & 20.5 & 84 &self-abs., \SOtwo \\
            & 13 &3--2 &  4.2 & --2.94& --2.1 & 12.0   & B &  \\
            & 18 &3--2 &  1.0 & --2.46& --- &      &   &  \\ 
G10.96+0.01E& 12 &3--2 & ${<}0.045$ & & & & & & & &  (1)\\
G10.96+0.01W& 12 &3--2 &${\sim}0.2$&30.0& ---& ${\sim}10$& &&& &marginal \\
G12.21-0.10 & 12 &3--2 & 5.8  & 24.1 & --- & 13.5 & & 16.2 & 12.8 & 71 &\SOtwo\\
G25.5+0.2A  & 12 &3--2 & ${<}0.20$  & & & & & & & &  (1)\\
G28.20-0.04N& 12 &3--2 & 3.6  &  ?   & 45.0& 22.9 & & 16.6 & 14.2 & 73 &\HCOpd\ self-abs.; \SOtwo \\
            & 13 &3--2 & 0.61 & 43.0 & 44.3& 11.9 & B &  \\
            & 18 &3--2 & 0.13 & 44.0 & --- &      &   & \\ 
G28.20-0.04S& 12 &1--0 & 0.22 & 41.5 & --- & ${\sim}8$& C &&&  &  \\
G28.28-0.36 & 12 &3--2 & 1.9  & 47.1 & --- & ${\sim}12$  &\\
G29.96-0.02 & 12 &3--2 & 9.6  & 97.7 & --- & 10.9 & & 19.2 & 17.6 & 62 &wings ?\\
G30.54+0.02 & 12 &3--2 & 2.8  & 48.3 & --- & 8.1 & & 21 & 18 & $--12$ &red em. wing \\
G31.41+0.31 & 12 &3--2 & 3.1  &  ?   & 98.5& ${\sim}23$ & & 18 & 14 & 65 &\HCOp\ self-abs. below cont;\SOtwo\\
            & 13 &3--2 & 1.4  & 98.0 & 98.8& 9.6  & B &&& & line-rich \\ 
G32.80+0.19 & 12 &3--2 & 4.2  &  ?   & 14.5& 17.3 & & 20 & 19 & $-11$ &broad self-abs. \\
            & 13 &3--2 & 1.3  & 14.9 & 14.1& 12.9 & B &  \\ 
G33.13-0.09 & 12 &3--2 & 1.6  & 76.6 & 76.4& 12.7 & & 25 & 17 & $-85$ \\
            & 13 &3--2 & 0.32 & 76.6 & 76.1&  7.5 & R &  \\ 
G33.560+0.20& 12 &3--2 & ${<}0.09$ & & & & & & & &  (1) \\
G34.26+0.15B& 12 &3--2 & 13.2 &  ?   & 60.8& 14.3 & & 29 & 25 & $-27$ & \SOtwo, OCS, line-rich\\
            & 13 &3--2 &  2.8 & 58.7 & 60.1&  8.7 & B &  \\ 
G35.20-1.74 & 12 &3--2 & 6.5  &  ?   & 43.7& 11.3 & & 27 & 26 & 61 \\
            & 13 &3--2 & 0.94 & 44.5 & 43.5& 7.9  & R &  \\
            & 18 &3--2 & 0.11 & 45.5 & --- &      &   & \\ 
G41.71+0.11 & 12 &3--2 & $<0.11$  & & & & & & & &  (1)\\
G43.89-0.78 & 12 &3--2 & 1.8  &  ?   & 55.2& ${\sim}15$ & & 21 & 21 & --4 \\
            & 13 &3--2 & 0.64 & 54.0 & 55.1& 6.5  & R &  \\ 
G45.07+0.13 & 12 &3--2 & 6.4  &  ?   & --- & 20.7 & & 15 & 14 & $-79$ &asymm. profile \\ 
            & 13 &3--2 & 1.2  & 58.0 &     & 10.8 & &  \\ 
G45.12+0.13 & 12 &3--2 &  6.3 & 59.8 & --- & 11.6 & & 38 & 35 & 28 &red em. wing \\
W51D        & 12 &3--2 & 14.9 & ${\sim}60.0$ & 51.1& 20.8 & & 21 & 15 & $-86$ &complex profile, \SOtwo\\
            & 13 &3--2 & 1.9  & 60.9 & 11.6&${\sim}52$& R &  \\
            & 12 &1--0 & 10.5 & ${\sim}60.0$ & 52.6& 16.8 & &&& &complex profile \\ 
G70.29+1.60 & 12 &3--2 &  8.5 & --23.0& --- & 14.6 & & 24 & 19 & $-87$ &weak wings\\
            & 12 &1--0 &  7.9 & --23.9& --- & 15.2 & &&& &weak wings \\ 
G81.67+0.53 & 12 &3--2 & 12.3 &  ?   & --1.8& 27.2 & & 33 & 27 & 4 &weak wings \\
            & 13 &3--2 &  2.1 & --3.3 & --1.9& 11.9 & B &  \\ 
G81.68+0.54 & 12 &3--2 & 4.1  & --2.7 & --2.4& 25.9 & &&& &weak wings \\
            & 13 &3--2 & 1.8  & --2.5 & --2.2&  4.6 & B &  \\ 
G111.612    & 12 &1--0 &  6.0 &--56.6 & --- & 5.9  & &\\
NGC 7538IRS1 & 12 &3--2 &  7.5 &--57.5 & --- & 13.7 & & 59 & 48 & 48 & complex profile, red wing \\
NGC 7538IRS2 & 12 &1--0 &  2.9 &--60.0 &--62.7& 17.8 & &&& &complex profile, wings\\ 
\hline
\end{tabular}
\tablefoot {The size of the \HCOpd\ source is approximated by an ellipse with major axis~$\Delta l$, its position angle~PA, and minor axis~$\Delta b$. \\
\tablefoottext{a}{Typical rms errors are 150, 50, and 20~mK for the \HCOp, H$^{13}$CO$^+$, and HC$^{18}$O$^+$~isotopes (see also Fig.~\ref{f:isotopes});}  
\tablefoottext{b}{errors are ${\la}0.8$~\km\  (half the channel spacing);}
\tablefoottext{c}{the error is ${\la}1$~\km\ for values preceded by~$\sim$, the other values have errors of ${\sim}0.1$~\km.}  \\
(1)~1$\sigma$ upper limit for 2.1~\km\ spectral resolution over a~${\pm}80$~\km\ range;  ?~line profile too complex.}
\vspace*{6.8mm}
\end{table}