  Brief HST/STIS spectroscopic snapshot exposures of the cataclysmic variables
1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg reveal very large NV/CIV line
flux ratios, similar to those observed in AE Aqr. Such anomalous line flux
ratios have so far been observed in 10 systems, and presumably reflect a
different composition of the accreted material compared to the majority of
cataclysmic variables. We discuss the properties of this small sample in the
context of the recent proposal by Schenker et al. (2002) that a significant
fraction of the present-day population of cataclysmic variables may have passed
through a phase of thermal time-scale mass transfer.
