  Lithium abundances are presented for a sample of 181 nearby F and G dwarfs
with accurate {\it Hipparcos} parallaxes. The stars are on circular orbits
about the Galactic centre and, hence, are identified as belonging to the thin
disk.
  This sample is combined with two published surveys to provide a catalogue of
lithium abundances, metallicities ([Fe/H]), masses, and ages for 451 F-G
dwarfs, almost all belonging to the thin disk. The lithium abundances are
compared and contrasted with published lithium abundances for F and G stars in
local open clusters. The field stars span a larger range in [Fe/H] than the
clusters for which [Fe/H] $\simeq 0.0\pm0.2$. The initial (i.e., interstellar)
lithium abundance of the solar neighborhood, as derived from stars for which
astration of lithium is believed to be unimportant, is traced from
$\log\epsilon$(Li) = 2.2 at [Fe/H] = -1 to $\log\epsilon$(Li) = 3.2 at $+0.1$.
This form for the evolution is dependent on the assumption that astration of
lit hium is negligible for the stars defining the relation. An argument is
advanced that this latter assumption may not be entirely correct, and, the
evolution of lithium with [Fe/H] may be flatter than previously supposed. A
sharp Hyades-like Li-dip is not seen among the field stars and appears to be
replaced by a large spread among lithium abundances of stars more massive than
the lower mass limit of the dip. Astration of lithium by stars of masses too
low to participate in the Li-dip is discussed. These stars show little to no
spread in lithium abundance at a given [Fe/H] and mass.
