\begin{figure}[ht]
  \begin{center}
 \subfigure[Data 
Unit]{\scalebox{0.55}{\includegraphics{pictures/dataunit}}} \quad 
\subfigure[Multidata 
Unit]{\scalebox{0.55}{\includegraphics{pictures/multidataunit}}} \\  
\subfigure[Scroller 
Unit]{\scalebox{0.55}{\includegraphics{pictures/scrollerunit}}} \quad 
\subfigure[Filter Unit]{\scalebox{0.55}{\includegraphics{pictures/filterunit}}} 
\quad \subfigure[Index 
Unit]{\scalebox{0.55}{\includegraphics{pictures/indexunit}}} 

    \caption{Mögliche HTML-Darstellung der Unit Typen}
    \label{fig: units}

  \end{center}
\end{figure}.