volutes vs helices

Interestingly enough both words come from the same PIE root *wel- 'to turn', whence English to well. Volute is from Latin and helix from Greek. It's common for a PIE /w/ to be dropped, but sometimes it changes to a rough breathing /h/ in word-initial position and sometimes not. (cf. oinos ~ vinum 'wine', ergos ~ work 'work'.)

http://www.bartleby.com/61/roots/IE565.html