  The $C_{\lambda}$-extended oscillator spectrum generating algebra is shown to
be a $C_{\lambda}$-extended $(\lambda-1)$th-degree polynomial deformation of
su(1,1). Its coherent states are constructed. Their statistical and squeezing
properties are studied in detail. Such states include both some
Barut-Girardello and the standard $\lambda$-photon coherent states as special
cases.
