Resonant multiphoton detachment spectroscopy has been used to obtain vibrationally resolved spectra of the C (2) Pi <-- X (2) Pi electronic transitions In C-4(-), C-6(-), and C-8(-). Transitions due to vibrational excitations in the totally symmetric stretching modes as well as the bending modes are observed. The electron detachment dynamics subsequent to multiphoton absorption are studied by measuring the electron emission time profiles and electron kinetic energy distributions. The observation of delayed electron emission combined with the form of the electron kinetic energy distributions indicates that these species undergo the cluster equivalent of thermionic emission. This interpretation is supported by comparing the experimental results to a microcanonical model for cluster thermionic emission.