THE CIRCUMSTELLAR ENVIRONMENT OF THE FU ORIONIS PRE-OUTBURST CANDIDATE V1331-CYGNI

High resolution (approximately 4'') aperture synthesis maps of the CO (1 --> 0), (CO)-C-13 (1 --> 0), (CO)-C-13 (2 --> 1), and associated continuum emission from the FU Orionis candidate V1331 Cygni reveal a massive, 0.5 +/- 0.15 M., circumstellar disk surrounded by a flattened gaseous envelope, 6000 X 4400 AU in size, mass greater-than-or-equal-to 0.32 M.. These images and lower resolution measurements also trace a bipolar outflow and gaseous ring, 4.1 by 2.8 X 10(4) AU, mass greater-than-or-equal-to 0.07 M., radially expanding at 22 +/- 4 km s-1. We suggest this ring is a swept-up gaseous torus from an energetic mass ejection stage, possibly an FU Orionis outburst or outbursts, approximately 4 X 10(3) yr ago that imparted greater-than-or-equal-to 10(45) ergs into the ambient cloud.