Study of galaxies in the Lynx-Cancer void. VI. HI-observations with the
  Nancay Radio Telescope
  Context. Void population consists mainly of late-type and low surface
brightness (LSB) dwarf galaxies whose atomic hydrogen is the main component of
their baryonic matter. Therefore, observations of void galaxy HI are mandatory
in order to understand their evolution and dynamics.
  Aims. Our aim was to obtain integrated HI parameters for a fainter part of
the nearby Lynx-Cancer void galaxy sample (total of 45 objects) with the Nancay
Radio Telescope (NRT) and to conduct the comparative analysis of all the 103
void galaxies with known HI data with a sample of similar galaxies residing in
denser environments of the Local Volume.
  Methods. For HI observations we used the NRT with its sensitive
antenna/receiver system FORT and standard processing. The comparison of the
void and control samples on the parameter M(HI)/L_B is conducted with the
non-parametric method `The 2x2 Contingency Table test'.
  Results. We obtained new HI data for about 40% of the Lynx-Cancer galaxy
sample. Along with data from the literature, we use these new data for further
analysis of 103 void objects. The proxy of the evolutional parameter M(HI)/L_B
of the void sample is compared with that of 82 galaxies of morphological types
8--10 residing in the Local Volume (LV) groups and aggregates.
  Conclusions. At the confidence level of P = 0.988, we conclude that for the
same luminosity, these void galaxies are systematically gas-richer, on average
by ~39%. This result is consistent with the authors' earlier conclusion on the
smaller gas metallicities and evidence for the slower low-mass galaxy evolution
in voids.
