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