Conic linear series and pencils of plane quartics

We study linear systems cut out by cones of fixed degree on a smooth complex curve $C\subset\mathbb{P}^{3}$.

We develop a systematic study of the families of such systems, considering their limits, their infinitesimal behaviour and some associated geometric structures.

As an application, we prove the existence of a non-isotrivial pencil of quartics with only one base point, all whose members are irreducible and whose general member is smooth.