  We present angular size measurements of 22 oxygen-rich Mira variable stars.
These data are part of a long term observational program using the Infrared
Optical Telescope Array (IOTA) to characterize the observable behavior of these
stars. Complementing the infrared angular size measurements, values for
variable star phase, spectral type, bolometric flux and distance were
established for stars in the sample; flux and distance led to values for
effective temperature, and linear radius, respectively. Additionally, values
for the K-[12] color excess were established for these stars, which is
indicative of dusty mass loss. Stars with higher color excess are shown to be
systematically 120 solar radii larger than their low color excess counterparts,
regardless of period. This analysis appears to present a solution to a
long-standing question presented by the evidence that some Mira angular
diameters are indicative of first overtone pulsation, while other diameters are
more consistent with fundamental pulsation. A simple examination of the
resultant sizes of these stars in the context of pulsation mode is consistent
with at least some of these objects pulsating in the fundamental mode.
