Let D be a set of positive integers. Let m(n) be the number of n edged
rooted maps on the sphere all of whose vertex degrees (or, dually, fa
ce degrees) lie in D. Using Brown's technique, the generating function
for m(n) implicitly is obtained. It is used to prove that, when gcd (
D) is even, m(n) similar to C(D)n(-5/2)gamma(D)(n). It also yields kno
wn-formulas for various special D.