  We revisit the shapes of isophotes for elliptical (E) and lenticular (S0)
galaxies by studying 847 nearby early-type galaxies selected from the Sloan
Digital Sky Survey Data Release 4 with velocity dispersions above 200 km/s. The
IRAF task {\tt ellipse} was used to derive the deviations of the isophotes from
pure ellipses (Fourier coefficients a_3/a and a_4/a), position angles and
ellipticities as a function of radius. We show the statistical distributions of
the a_3/a and a_4/a parameters as a function of velocity dispersion, magnitude,
and colour. The a_4/a parameter is correlated with the ellipticity and absolute
Petrosian magnitude of galaxies. No significant correlation was found between
the a_4/a parameter with colour and velocity dispersion. A cross-correlation
between the FIRST survey and the SDSS data reveals a lack of powerful radio
emitters in discy E/S0s, as previously found by Bender et al. We also find that
boxy E/S0s favor denser environments while discy E/S0s favor more isolated
environments. The median values of changes in the ellipticity and position
angle between one and one and a half Petrosian half-light radii in the
isophotes are about -0.023 and 1.61 degree respectively. The average change in
the position angle is much larger, about 4.12 degree, due to an extended tail.
The change in ellipticity is weakly correlated with the ellipticity itself,
with an increasing ellipticity for galaxies with higher ellipticity as the
radius increases. The isophote parameters for the 847 galaxies are available
online.
