  Symbolic methods of umbral nature play an important and increasing role in
the theory of special functions and in related fields like combinatorics. We
discuss an application of these methods to the theory of lacunary generating
functions for the Laguerre polynomials for which we give a number of new closed
form expressions. We present furthermore the different possibilities offered by
the method we have developed, with particular emphasis on their link to a new
family of special functions and with previous formulations, associated with the
theory of quasi monomials.
