Bacili or Bacilli: How To spell?
The word Bacili is misspelled against Bacilli, which is plural of "Bacillus"
Bacilli has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings baci & i which should not be misspelled with single 'L'
Wrong Spelling:  baci-l-i  Correct Spelling:  baci-ll-i 
Find more wrongly spelled words of Bacilli to spell it well.