Perenibranchiate or Perennibranchiate: How To spell?
The word Perenibranchiate is misspelled against Perennibranchiate, an adjective meaning "Belonging to the Perennibranchiata."
Perennibranchiate has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings pere & ibranchiate which should not be misspelled with single 'N'
Wrong Spelling:  pere-n-ibranchiate  Correct Spelling:  pere-nn-ibranchiate 
Find more wrongly spelled words of Perennibranchiate to spell it well.