{HEAD ~ a rupturable membrane} sealed to said annular surface by {TAIL ~ a continuous seal} around said opening, said continuous seal being located on said annular surface 
sealed by
{ HEAD ~ a rupturable membrane } sealed to said annular surface by { TAIL ~ a continuous seal } around said opening , said continuous seal being located on said annular surface
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH