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