{HEAD ~ Each} of the end walls has a first end, {TAIL ~ a second end} and a free side from which a horizontal plate extends transversely 
has
{ HEAD ~ Each } of the end walls has a first end , { TAIL ~ a second end } and a free side from which a horizontal plate extends transversely
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH