Menn's Surface

A surface given by the parametric equations

$$x(u,v) = u$$

$$y(u,v) = v$$

$$z(u,v) = au^4+u^2v-v^2.$$

References

Gray, A. Modern Differential Geometry of Curves and Surfaces. Boca Raton, FL: CRC Press, p. 631, 1993.