{HEAD ~ The two groovelike indentations} 17 on both sides of the insertion slit 9 are in {TAIL ~ alignment} with one another and with the insertion slit 
are in
{ HEAD ~ The two groovelike indentations } 17 on both sides of the insertion slit 9 are in { TAIL ~ alignment } with one another and with the insertion slit
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH