Interexes or Interrexes: How To spell?
The word Interexes is misspelled against Interrexes, which is plural of "Interrex"
Interrexes has double "rr" is mispronounced as "r"Remember double 'RR' in between the strings inte & exes which should not be misspelled with single 'R'
Wrong Spelling:  inte-r-exes  Correct Spelling:  inte-rr-exes 
Explore spell check of Interrexes to spell without errors.