  We analyze Herschel Space Observatory observations of 104 young stellar
objects with protoplanetary disks in the ~1.5 Myr star-forming region Lynds
1641 (L1641) within the Orion A Molecular Cloud. We present spectral energy
distributions from the optical to the far-infrared including new photometry
from the Herschel Photodetector Array Camera and Spectrometer (PACS) at 70
microns. Our sample, taken as part of the Herschel Orion Protostar Survey,
contains 24 transitional disks, eight of which we identify for the first time
in this work. We analyze the full disks with irradiated accretion disk models
to infer dust settling properties. Using forward modeling to reproduce the
observed nKS-[70] index for the full disk sample, we find the observed disk
indices are consistent with models that have depletion of dust in the upper
layers of the disk relative to the mid plane, indicating significant dust
settling. We perform the same analysis on full disks in Taurus with Herschel
data and find that Taurus is slightly more evolved, although both samples show
signs of dust settling. These results add to the growing literature that
significant dust evolution can occur in disks by ~1.5 Myr.
