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