The terminology typically used for bodies physically rotating on their minor axis not necessarily ellipsoids of revolution, in their mathematical construction and whose shape is determined by their gravitational field is " "'Maclaurin spheroid " "'( oblate spheroid ) and " "'Jacobi ellipsoid " "'( scalene ellipsoid ).
22.
Modern geodesy tends to retain the ellipsoid of revolution and treat triaxiality and pear shape as a part of the geoid figure : they are represented by the spherical harmonic coefficients C _ { 22 }, S _ { 22 } and C _ { 30 }, respectively, corresponding to degree and order numbers 2.2 for the triaxiality and 3.0 for the pear shape.
