  Using both the Arecibo 305m and the Nancay decimetric 100-m class radio
telescopes, we have observed the HI line of 116 Low Surface Brightness (LSB)
galaxies from the Bothun et al. 1985 subset of LSB galaxies in the Uppsala
General Catalog. The observations had a detection rate of 70%, resulting in the
new determination of HI properties for 81 galaxies. Surprisingly, roughly half
of the detected objects (38) have M_HI >= 10^10 M_sol, placing them into the
category of massive LSB galaxies. As previously only ~18 of these `Malin 1
cousins' were known, our results have more than tripled the number of these
fascinating and enigmatic systems known.
  Combining our results with previous studies done on the Bothun et al. catalog
results in a well-defined catalog of HI properties of 526 LSB galaxies ranging
in redshift space from 0 <= z <= 0.1. With this catalog in hand, we have been
able to explore the parameter space occupied by LSB galaxies more completely
than has been previously possible. In agreement with previous studies, our
results show LSB galaxies with some of the most extreme properties of disk
galaxies, including M_HI/L_B ratios often exceeding 10 M_sol/L_sol,B.
