FIG 8 also shows the spherical indented shape of {TAIL ~ the two outside walls} 216 which are formed by {HEAD ~ a subsequently applied covering} 
FIG 8 also shows the spherical indented shape of { TAIL ~ the two outside walls } 216 which are formed by { HEAD ~ a subsequently applied covering }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD