  This paper is a continuation of our study of compact, power compact, Riesz,
and quasicompact endomorphisms of commutative Banach algebras. Previously it
has been shown that if $B$ is a unital commutative semisimple Banach algebra
with connected character space, and $T$ is a unital endomorphism of $B$, then
$T$ is quasicompact if and only if the operators $T^n$ converge in operator
norm to a rank-one unital endomorphism of $B$.
  In this note the discussion is extended in two ways: we discuss endomorphisms
of commutative Banach algebras which are semiprime and not necessarily
semisimple; we also discuss commutative Banach algebras with character spaces
which are not necessarily connected.
  In previous papers we have given examples of commutative semisimple Banach
algebras $B$ and endomorphisms $T$ of $B$ showing that $T$ may be quasicompact
but not Riesz, $T$ may be Riesz but not power compact, and $T$ may be power
compact but not compact. In this note we give examples of commutative,
semiprime Banach algebras, some radical and some semisimple, for which every
quasicompact endomorphism is actually compact.
