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   72021
   A small number of cataclysmic variables show no observable traces of
   hydrogen. A likely model involves a white dwarf accreting from a Roche-
   lobe filling, less massive, He white dwarf secondary. The peculiar
   evolutionary history implied by such a configuration may result in
   other abundance anomalies, besides the lack of hydrogen. I have
   analyzed the archival ASCA AO-2 data on one such system, GP Com; I have
   been able to derive, solely from the X-ray spectrum, overabundances of
   N and Ne and underabundance of Fe, as previously suggested from optical
   and UV spectroscopy. I propose to observe the next 3 X-ray brightest
   hydrogen deficient cataclysmic variables.
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