  In this note we prove the genus 3 case of a conjecture of G. Farkas and A.
Verra on the limit of the Scorza correspondence for curves with a theta-null.
Specifically, we show that the limit of the Scorza correspondence for a
hyperelliptic genus 3 curve C is the union of the curve ${x,\sigma(x))$ (where
$\sigma$ is the hyperelliptic involution), and twice the diagonal. Our proof
uses the geometry of the subsystem \Gamma_{00} of the linear system 2\Theta,
and Riemann identities for theta constants.
