{TAIL ~ said main portion} and tubular portion having an inner surface and {HEAD ~ a generally arcuate shaped outer surface} 
{ TAIL ~ said main portion } and tubular portion having an inner surface and { HEAD ~ a generally arcuate shaped outer surface }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD