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