Chondrostau or Chondrostei: How To spell?

The word Chondrostau 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 'AU'
Wrong Spelling:  chondrost-au 
Correct Spelling:  chondrost-ei 
Check more misspelled words of Chondrostei to spell it correct.