I am working with closed degenerating hyperbolic Riemann surfaces, and I try to understand the compactification of the moduli space. Looking in different books, notably the one of [Hummel][1], I now get a good intuition of what happens, but i have still not  found a reference  where this compactification is made precise in this setting. And I also look for a combinatorial description of what limit surface are possible? Even if I presume that all configuration are possible.
Thank You.

  [1]: http://books.google.fr/books/about/Gromov_s_Compactness_Theorem_for_Pseudo.html?id=f9iUssr7L_EC&redir_esc=y