Holostai or Holostei: How To spell?

The word Holostai is misspelled against Holostei, a noun meaning "An extensive division of ganoids, including the gar pike, bowfin, etc.; the bony ganoids. See Illustration in Appendix."

Word ends with consecutive vowels 'EI' preceded by alphabets 'holost' is misspelled as 'AI'
Wrong Spelling:  holost-ai 
Correct Spelling:  holost-ei 
Find more incorrect spellings of Holostei to spell right way.