{HEAD ~ further arcuate portions} continuously formed with said respective planar portions and matched to {TAIL ~ a portion} of the other arcuate portion of said elongated mating member, and 
matched to
{ HEAD ~ further arcuate portions } continuously formed with said respective planar portions and matched to { TAIL ~ a portion } of the other arcuate portion of said elongated mating member , and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH