Diatesaron or Diatessaron: How To spell?
The word Diatesaron is misspelled against Diatessaron, a noun meaning "A continuous narrative arranged from the first four books of the New Testament."
Diatessaron has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings diate & aron which should not be misspelled with single 'S'
Wrong Spelling:  diate-s-aron  Correct Spelling:  diate-ss-aron 
Find more incorrect spellings of Diatessaron to spell right way.