  We present kinematic measurements of the thick and thin disks in two edge-on
galaxies. We have derived stellar rotation curves at and above the galaxies'
midplanes using Ca II triplet features measured with the GMOS spectrograph on
Gemini North. In one galaxy, FGC 1415, the kinematics above the plane show
clear rotation that lags that of the midplane by ~20-50%, similar to the
behavior seen in the Milky Way. However, the kinematics of the second galaxy,
FGC 227, are quite different. The rotation above the plane is extremely slow,
showing <25% of the rotation speed of the stars at the midplane. We decompose
the observed rotation curves into a superposition of thick and thin disk
kinematics, using 2-dimensional fits to the galaxy images to determine the
fraction of thick disk stars at each position. We find that the thick disk of
FGC 1415 rotates at 30-40% of the rotation speed of the thin disk. In contrast,
the thick disk of FGC 227 is very likely counter-rotating, if it is rotating at
all. These observations are consistent with the velocity dispersion profiles we
measure for each galaxy. The detection of counter-rotating thick disks
conclusively rules out models where the thick disk forms either during
monolithic collapse or from vertical heating of a previous thin disk. Instead,
the data strongly support models where the thick disk forms from direct
accretion of stars from infalling satellites.
