ing two classes of ultralong-range Rydberg molecules known as trilobite" and<br>
butter<br>
y" molecules. These molecules are predicted to have giant, body- xed<br>
permanent dipole moments on the order of 1000 Debye. The two classes of<br>
molecules are distinguished by the relative dominance of the s-wave and p-wave<br>
electron scattering. We present spectra for (nS1=2 +6S1=2)3 molecules, where<br>
n = 37, 39 and 40, and measurements of the Stark broadenings of selected<br>
trilobite states in Cs due to the application of a constant external electric eld.<br>
Additionally, we present measurements of spectra and Stark splittings for p-<br>
wave dominated (nS1=2 + 6S1=2)3 molecules, where n = 31 and 32.<br>