[GRASSLIST:3379] Removing boundaries on vector maps

[SWlab]

Hello,
I have a number of vector maps, each representing stream paths over a USGS 
7.5' quad. The boundaries of the quads are present on each map. Is there a 
scriptable way to remove those boundaries before or after patching the maps ?
Thanks for any hint

-- 
Soil & Water Laboratory
Dept. of Biological & Environmental Engineering
Cornell University
ITHACA, NY 14853
Tel: (607)255.2463