Lantry > Langtry
English: habitational name from places in
Devon, Oxfordshire, and Lancashire called Langtree, from Old English lang, long ‘long’, ‘tall’ + trēow ‘tree’.
Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4
quoted by:
http://www.ancestry.com/search/SurnamePage.aspx?ln=Langtry&fn=&sourcecode=13304&html=b