Monodromy representations of hypergeometric systems with respect to fundamental series solutions

We study the monodromy representation of the generalized hypergeometric differential equation and that of Lauricella's $F_C$ system of hypergeometric differential equations. We use fundamental systems of solutions expressed by the hypergeometric series. We express non-diagonal circuit matrices as reflections with respect to root vectors with all entries $1$. We present a simple way to obtain circuit matrices.