  Electromagnetic waves, in vacuum or dielectrics, can be confined in unbounded
cylinders in such a way that they turn around the main axis. For particular
choices of the cylinder's section, interesting stationary configurations may be
assumed. By refining some results obtained in previous papers, additional more
complex situations are examined here. For such peculiar guided waves an
explicit expression is given in terms of Bessel's functions. Possible
applications are in the development of whispering gallery resonators.
