Chondrostay or Chondrostei: How To spell?

The word Chondrostay is misspelled against Chondrostei, a noun meaning "An order of fishes, including the sturgeons; -- so named because the skeleton is cartilaginous."

Word ends with consecutive vowels 'EI' preceded by alphabets 'chondrost' is misspelled as 'AY'
Wrong Spelling:  chondrost-ay 
Correct Spelling:  chondrost-ei 
Find more incorrect spellings of Chondrostei to spell right way.