an elongated hopper door extending across {HEAD ~ the full width} of {TAIL ~ the box} along the bottom of the hopper to form a part of the bottom thereof 
of
an elongated hopper door extending across { HEAD ~ the full width } of { TAIL ~ the box } along the bottom of the hopper to form a part of the bottom thereof
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH