What name is given to the space between a persons extended thumb & index finger ?

The word for the space between the thumb and the index finger is "purlicue."

"purlicue   pur li kuu  (noun)
    : the space between the thumb and extended forefinger"

Word a Day Weekly Word Match
http://archives.gophercentral.com/index.php?op=news&id=807

"purlicue
 n. space between extended thumb and index finger"

Tiscali Reference Dictionary: Difficult Words
http://www.tiscali.co.uk/reference/dictionaries/difficultwords/data/d0010649.html

"Purlicue: the space between the extended thumb and index finger."

The San Diego Union-Tribune: Eureka!
http://www.signonsandiego.com/uniontrib/20041110/news_lz1c10eureka.html 

"When you spread your hand, what's that skin between your 
 thumb and forefinger called?
  Purlicue" 

DennisWeb: Human Trivia
http://www.dennisweb.com/trivia/human_01.htm

Google search strategy: 

Google Web Search: purlicue
://www.google.com/search?hl=en&q=purlicue

I hope this is helpful. If anything is unclear or incomplete, or if a
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Best regards,
pinkfreud