One of the three classes of Tori illustrated above and given by the parametric equations
The standard tori and their inversions are Cyclides.
See also Apple, Cyclide, Horn Torus, Lemon, Ring Torus, Spindle Torus, Torus
Pinkall, U. ``Cyclides of Dupin.'' §3.3 in
Mathematical Models from the Collections of Universities and Museums (Ed. G. Fischer).
Braunschweig, Germany: Vieweg, pp. 28-30, 1986.