a) What is the name given to the rays, traveling from cathode to anode?
b) Do the cathode rays always consist of electrons only, whatever be the gas enclosed in the discourage tube?

a) The rays, traveling from cathode to anode in the discharge tube, are called cathode rays.
b) Yes, cathode rays always consist of a stream of electrons whatever be the gas enclosed, because on passing high voltage of current through the rarefied gas, the electrons from the atom are knocked out and form cathode rays.