& y^{2}=(x-\mu_{s-3,1})(x-\mu_{s-3,2})(x-\mu_{s-2,1})(x-\mu_{s-2,2})\\
        E_{s}: & y^{2}=x(x-\mu_{s-2,1})(x-\mu_{s-2,2})
        \end{array}$$

    3.  It happens that $S$ is an irreducible connected component of the fiber product of the pairs $(E_{1},\pi_{1}),\ldots,(E_{s},\pi_{s})$, where $\pi_{j}(x,y)=x$.

An example of genus nine
------------------------

The construction provided in Theorem \[construccion\] permits to obtain Riemann surfaces whose jacobian variety is isogenous to the product of elliptic curves. Next, as an example, we describe a $2$-dimensional family of genus nine Riemann surfaces whose jacobian is isogenous to the product of nine elliptic curves.

\[coro3\] Let $(\lambda, \mu) \in \Delta_{2}$ and set $$\mu_{1,1}=\mu, \; \mu_{1,2}=\frac{\lambda}{\mu}, \; \mu_{2,1}=\frac{\lambda(\mu-1)}{\mu-\lambda}, \; \mu_{2,2}=\frac{\mu-\lambda}{\mu-1},$$ $$K_{1}=(\mu_{2,2}-\mu_{1,1})(\mu_{2,2}-\mu_{1,2})(\mu_{2,2}-\mu_{2,1}), \;
K_{2}=(\mu_{2,2}-1)(\mu_{2,2}-\lambda)(\mu_{2,2}-\mu_{2,1}),$$ $$K_{3}=(\mu_{2,2}-1)(\mu_{2,2}-\lambda)(\mu_{2,2}-\mu_{1,1})(\mu_{2,2}-\mu_{1,2}), \;
K_{4}=-\mu_{2,2}(\mu_{2,2}-\mu_{2,1}),$$ $$K_{5}=-\mu_{2,2}(\mu_{2,2}-\mu_{1,1})(\mu_{2,2}-\mu_{1,2}), \;
K_{6}=-\mu_{2,2}(\mu_{2,2}-1)(\mu_{2,2}-\lambda).$$

If $S$ is the genus nine Riemann surface defined by the curve $$\left\{\begin{array}{lcl}
w_{1}^{2}&=&K_{1}
\left(z-\dfrac{1}{\mu_{1,1}-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{1,2}-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{2,1}-\mu_{2,2}} \right)  \\
w_{2}^{2}&=&K_{2}
\left(z-\dfrac{1}{1-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\lambda-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{2,1}-\mu_{2,2}} \right)  \\
w_{3}^{2}&=&K_{3}
\left(z-\dfrac{1}{1-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\lambda-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{1,1}-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{1,2}-\mu_{2,2}} \right)  \\
w_{4}^{2}&=&K_{4}
z\left(z+\dfrac{1}{\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{2,1}-\mu_{2,2}} \right)  \\
w_{5}^{2}&=&K_{5}
z\left(z+\dfrac{1}{\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{1,1}-\mu_{2,2}} \right)
\left(z-\dfrac{1}{\mu_{1,2}-\mu_{2,2}} \right)  \\
w_{6}^{2}&=&K_{6}
z\left(z+\dfrac{1}{\mu_{2,2}} \right)
\left(z-\dfrac{1}{1-(\mu_{2,2}} \right)
\left(z-\dfrac{1}{\lambda-\mu_{2,2}} \right)  \\
w_{7}^{2}&=&w_{3}^{2}w_{4}^{2}
\end{array}
\right\}$$ then $JS$ is isogenous to the product of nine elliptic curves.

Genus three case
----------------

As previously noted in the introduction, for every triple $(E_{1},E_{2},E_{3})$ of elliptic curves there is some genus three 