  We present the first results of a study of the kinematics and morphology of
ultracompact HII regions using a new observational technique. We used very high
spatial (1.5") and spectral (3.4 km/s)resolution observations of the [NeII]
line at 12.8 microns to study the ionized gas in Monoceros R2. The [NeII]
emission shows an HII region with highest emission measure in a ~24" shell.
Line widths are as narrow as 8 km/s at some positions. In places where the
lines are complex and broader, the additional width is most likely due to
overlap of narrower features along the line of sight. The global kinematics
suggest that the 24" shell is expanding at ~10 km/s. However, the spectral
profiles toward the southeast side of the shell are not consistent with a
simple expansion picture.
