**5. Acknowledgment**

The author acknowledges FAPESP for financial support (Proj. #2000/15087-4 and #2010/09277-7). University of São Paulo is acknowledged for the financial support of this book chapter. Prof. Carlos Bonafé is kindly acknowledged for his help and support to the preparation of the *G. Paulistus* samples. The author is grateful to Profa. Iris Torriani for several valuable discussions.
