The magnetic moments of Eu, Nd and Pr single crystals have been measured between 2 °K and 300 °K in fields up to 60 kG. The effective moments in the paramagnetic phase have been obtained. The magnetic transitions in Nd at low temperatures are observable as anomalies in the low field susceptibility. The low temperature susceptibility of Pr is much greater in the basal plane than along the c-axis, and tends to saturate at high fields. Eu has a first-order transition to a magnetically ordered phase at 94.3 °K ; below this temperature the susceptibility is anisotropic and nonlinear