  We have carried out large scale 12CO and 13CO observations with a mm/sub-mm
telescope NANTEN toward a loop-like structure in far infrared whose angular
extent is about 20x20 degrees around (l, b) ~ (109, -45) in Pegasus. The 12CO
distribution is found to consist of 78 small clumpy clouds whose masses range
from 0.04 Mo to 11 Mo. About 83% of the 12CO clouds have very small masses less
than 1.0 Mo. 13CO emission shown in the 19 of the 78 12CO clouds was detected
in the region where the column density of H2 derived from 12CO is greater than
5x10(20) cm(-2), corresponding to Av of ~ 1 mag, which takes into account that
of HI. We find no indication of star formation in these clouds in IRAS and
2MASS Point Source Catalogs. The very low mass clouds, M < 1 Mo, identified are
unusual in the sense that they have very weak 12CO peak temperature of 0.5 K to
2.7 K and that they aggregate in a region of a few pc with no main massive
clouds of ~ 100 Mo. A comparison with a theoretical work on molecular cloud
formation (Koyama & Inutsuka 2002) suggests that the very low-mass clouds may
have been formed in the shocked layer through the thermal instability. The star
HD886 (B2IV) may be the source of the mechanical luminosity via stellar winds
to create shocks, forming the loop-like structure where the very low-mass
clouds are embedded.
