  We have mapped the central region of the HH 111 protostellar system in 1.33
mm continuum, C18O(J=2-1), 13CO (J=2-1), and SO (N_J=5_6-4_5) emission at ~3"
resolution with the Submillimeter Array. There are two sources, VLA 1 (=IRAS
05491+0247) and VLA 2, with the VLA 1 source driving the HH 111 jet. Thermal
emission is seen in 1.33 mm continuum tracing the dust in the envelope and the
putative disks around the sources. A flattened, torus-like envelope is seen in
C18O and 13CO around the VLA 1 source surrounding the dust lane perpendicular
to the jet axis, with an inner radius of ~ 400 AU (1"), an outer radius of ~
3200 AU (8"), and a thickness of ~ 1000 AU (2.5"). It seems to be infalling
toward the center with conservation of specific angular momentum rather than
with a Keplerian rotation as assumed by Yang et al. 1997. An inner envelope is
seen in SO, with a radius of ~ 500 AU (1.3"). The inner part of this inner
envelope, which is spatially coincident with the dust lane, seems to have a
differential rotation and thus may have formed a rotationally supported disk.
The outer part of this inner envelope, however, may have a rotation velocity
decreasing toward the center and thus represent a region where an infalling
envelope is in transition to a rotationally supported disk. A brief comparison
with a collapsing model suggests that the flattened, torus-like envelope seen
in C18O and 13CO could result from a collapse of a magnetized rotating toroid.
