a first opening in surface portions thereof adjacent said {HEAD ~ free extremity} and in communication with {TAIL ~ said passageway}, 
a first opening in surface portions thereof adjacent said { HEAD ~ free extremity } and in communication with { TAIL ~ said passageway } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH