  Mid-infrared spectrophotometric observations have revealed a small sub-class
of circumstellar disks with spectral energy distributions (SEDs) suggestive of
large inner gaps with low dust content. However, such data provide only an
indirect and model dependent method of finding central holes. We present here
the direct characterization of a 40 AU radius inner gap in the disk around LkHa
330 through 340 GHz (880 micron) dust continuum imaging with the Submillimeter
Array (SMA). This large gap is fully resolved by the SMA observations and
mostly empty of dust with less than 1.3 x 10^-6 M_solar of solid particles
inside of 40 AU. Gas (as traced by accretion markers and CO M-band emission) is
still present in the inner disk and the outer edge of the gap rises steeply --
features in better agreement with the underlying cause being gravitational
perturbation than a more gradual process such as grain growth. Importantly, the
good agreement of the spatially resolved data and spectrophometry-based model
lends confidence to current interpretations of SEDs with significant dust
emission deficits as arising from disks with inner gaps or holes. Further
SED-based searches can therefore be expected to yield numerous additional
candidates that can be examined at high spatial resolution.
