CCD spectrophotometry of CVs. I. 4600-9000A low resolution atlas for 31 faint systems.

A low resolution (~18A) 4600-9000A spectrophotometric atlas is presented for 31 objects in the Downes & Shara (1993) catalogue of Cataclysmic Variables. The star were selected among those listed without published quiescence spectra. All the spectra we present pertain to photometric quiescence phases. V-R, R-I colors, continuum fluxes at selected wavelengths, equivalent widths of emission lines and description of absorption lines and bands are given for all the programme stars. Of the 31 systems surveyed, 19 have spectra confirming their classification as CVs, 8 show continua without emission lines, one is a planetary nebula, another one could be a symbiotic star and one turned out to be a starburst galaxy.