Hydrocavlus or Hydrocaulus: How To spell?
The word Hydrocavlus is misspelled against Hydrocaulus, a noun meaning "The hollow stem of a hydroid, either simple or branched. See Illust. of Gymnoblastea and Hydroidea."
Word contains consecutive vowels 'AU' in between alphabets hydroc & lus is misspelled as 'AV'Wrong Spelling:  hydroc-av-lus  Correct Spelling:  hydroc-au-lus 
Check more misspelled words of Hydrocaulus to spell it correct.