  We present long slit Halpha observations of 50 low surface brightness
galaxies. Of these, 36 are of sufficient quality to form rotation curves. These
data provide a large increase in the number of low surface brightness galaxies
for which accurate rotation curves are available. They also represent an order
of magnitude improvement in spatial resolution over previous 21 cm studies (1"
to 2" instead of 13" to 45"). The improved resolution and accuracy of the data
extend and strengthen the scientific conclusions previously inferred from 21 cm
data.
