Notches 324 are formed along {TAIL ~ the outer peripheral edge} of {HEAD ~ the base portion} 318 
Notches 324 are formed along { TAIL ~ the outer peripheral edge } of { HEAD ~ the base portion } 318
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH