  We show that the observational data recently provided by Giovanelli et al.
(1996 a, b) and discussed by Bahcall and Oh (1996) concerning the velocity
distribution of clusters of galaxies can be naturally fitted by a statistical
distribution which generalizes the Maxwell-Boltzmann one (herein recovered for
the entropic index $q=1$). Indeed a recent generalization of the
Boltzmann-Gibbs thermostatistics suggests for this problem that the probability
function is given, within a simple phenomenological model, by \begin{eqnarray}
P(>v) & = & \frac{ \int_{v}^{v_{max}} dv \left[ 1-(1-q)(v/v_0)^2
\right]^\frac{q}{1-q} } {\int_{0}^{v_{max}} dv \left[ 1-(1-q)(v/v_0)^2
\right]^\frac{q}{1-q}}, \nonumber \\ v_{max} & \equiv & \left\{
\begin{array}{ll} v_0 (1-q)^{-1/2} & \mbox{if $q<1$} \\ \infty & \mbox{if $q
\geq 1$.} \end{array}\right. \nonumber \end{eqnarray} A remarkably good fitting
with the data is obtained for $q=0.23^{+0.07}_{-0.05}$ and $v_0=490\pm 5$ km
s$^{-1}$.
