\newcounter{subsubsubsection}[subsubsection]
\def\subsubsubsectionmark#1{}
\def\thesubsubsubsection {\thesubsubsection
     .\arabic{subsubsubsection}}
\def\subsubsubsection{\@startsection
     {subsubsubsection}{4}{\z@} {-3.25ex plus -1
     ex minus -.2ex}{1.5ex plus .2ex}{\normalsize\bf}}
\def\l@subsubsubsection{\@dottedtocline{4}{4.8em}
     {4.2em}}

\newcounter{subsubsubsubsection}[subsubsubsection]
\def\subsubsubsubsectionmark#1{}
\def\thesubsubsubsubsection {\thesubsubsubsection
     .\arabic{subsubsubsubsection}}
\def\subsubsubsubsection{\@startsection
     {subsubsubsubsection}{5} {\z@} {-3.25ex plus -1
     ex minus -.2ex}{1.5ex plus .2ex}{\normalsize\bf}}
\def\l@subsubsubsubsection{\@dottedtocline{5}
     {5.8em}{5.2em}}