The recesses 16′ have {HEAD ~ at least one wall} 20′ extending from {TAIL ~ the associated base} 12′ 
extending from
The recesses 16′ have { HEAD ~ at least one wall } 20′ extending from { TAIL ~ the associated base } 12′
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH