The catalogue consists of all the stars whose proper motion gives them
a greater than 90% chance of membership according to Mendoza
and Gomez (1980).  These hhave been crossed matched using the
id's of either Walker (1956) (field#=1) or Vasilevski (1965)
(field#=2) and Webda to find good J2000 positions (the Webda sources where
Tycho and USNOA2). These positions have then been matched and
subsequently replaced with 2mass co-ordinates.