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