Alvau or Alvei: How To spell?

The word Alvau is misspelled against Alvei, which is plural of "Alveus"

Word ends with consecutive vowels 'EI' preceded by alphabets 'alv' is misspelled as 'AU'
Wrong Spelling:  alv-au 
Correct Spelling:  alv-ei 
Check more misspelled words of Alvei to spell it correct.