{HEAD ~ arcuate portions} continuously formed with {TAIL ~ said one planar portion} and matched to one of said arcuate portions of said elongated mating member, 
continuously formed with
{ HEAD ~ arcuate portions } continuously formed with { TAIL ~ said one planar portion } and matched to one of said arcuate portions of said elongated mating member ,
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH