A cell of the outer peripheral side honeycomb unit in contact with the outermost peripheral cell wall thereof has {HEAD ~ a corner part} having {TAIL ~ a curved surface}, where the corner part is on the side contacting the outermost peripheral cell wall 
having
A cell of the outer peripheral side honeycomb unit in contact with the outermost peripheral cell wall thereof has { HEAD ~ a corner part } having { TAIL ~ a curved surface } , where the corner part is on the side contacting the outermost peripheral cell wall
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH