Using the IRAM 30 m telescope two molecular structures have been detected which cover very small areas , FWHM \leq 1 ^ { \prime } .
The clouds have velocities of v _ { lsr } \approx 5 km s ^ { -1 } and linewidth of \Delta v \approx 0.8 km s ^ { -1 } ; thus they belong most likely to the Milky Way .
Applying standard conversion factors one finds that even at the upper distance limit of 2200 pc the structures are low mass objects ( M = ( 1 - 6 ) \times 10 ^ { -4 } \large ( { d \over 100 { pc } } \large ) ^ { 2 } M _ { \odot } ) which are not gravitationally virialized .
H I 21cm line data towards the clouds show no prominent HI clouds .
The total H I column densities for both structures are below N ( HI ) \leq 2.1 \times 10 ^ { 20 } cm ^ { -2 } , corresponding to A _ { V } \leq 0.2 mag , assuming a standard gas-to-dust ratio .
IRAS 100 \mu m data towards the structures show also only low emission , consistent with low extinction .
Unless there is unseen cold dust associated with the structures this shielding is too low for the structures to survive the interstellar radiation field for a long time .
The detection of 2 such structures in a rather limited sample of observations suggests that they could be a rather common feature in the interstellar medium , however , so far not recognized as such due to the weakness of their lines and their small extent .