We study a distinguished basis in the centre of the enveloping algebra
of the Lie superalgebra q(N). The irreducible polynomial representati
ons of q(N) are labelled by decreasing sequences of positive integers
lambda = (lambda(1),...,lambda(l)) with l less than or equal to N. The
elements of our basis are labelled by the same sequences. The basic e
lement C-lambda of the centre vanishes in the irreducible representati
on corresponding to a sequence mu if and only if lambda(i) > mu(i) for
some i. We obtain an explicit formula for the element C-lambda.