>>8
これで動くかな

#!/bin/sh
while read path
do
if [ -d "$path" ]; then
base_name=$(basename "$path")
dir_name=$(dirname "$path")
ext=".zip"
zip_name="$base_name$ext"
chdir "$dir_name"
zip -r "$zip_name" "$base_name"
fi
done <<END
$NAUTILUS_SCRIPT_SELECTED_FILE_PATHS
END