  Small-area molecular structures (SAMS) resembling those clumpuscules,
proposed by Pfenniger and Combes (1994) as candidate for baryonic dark matter,
have recently been detected (Heithausen 2002, 2004) in an area where the
shielding is too low for them to survive for a long time. To study the
frequency of occurence of such structures I present the results of an unbiased
deep search for molecular clumpuscules. The area surrounding these structures
has been surveyed using the FCRAO 14m telescope in the CO J=1-0 transition. The
field covered is 20' by 20'. The resulting rms of the data is only 0.04K in a
0.127 km/s wide channel. Also, high-angular resolution observations of the 13CO
and C18O (J=1-0) transitions were obtained with the IRAM Plateau-de-Bure
Interferometer. 3 new SAMS have been detected. The structures have very low
intensities which makes it impossible to detect them in large scale CO surveys
conducted to map the molecular gas of the Milky way. They move with a similar
radial velocity as the surrounding HI gas. The clouds follow the same
size-linewidth relation as found for giant molecular clouds or Galactic cirrus
clouds. The observations clearly show that most of the large linewidths
observed at low angular resolution is caused by a large velocity difference
among the clumps seen at highest angular resolution. At an adopted distance of
100pc the structures have masses of only Jupiter mass or below. My observations
show that SAMS might be an abundant phenomenon in the interstellar medium
however not recognized as such due to their small size. If they are made of
ordinary interstellar matter with solar metallicity they likely contribute only
little to the total interstellar mass.
