We have analyzed FUSE observations of six hot white dwarf stars : four DA white dwarfs with T _ { eff } \ga 45 000 K , the DAO Feige 55 ( T _ { eff } \approx 55 000 K ) , and the DA CD $ -38^ ∘ $ 10980 ( T _ { eff } \approx 24 000 K ) .
Photospheric lines from Si IV , P V , and S VI can be observed in the majority of the five hotter objects .
Feige 55 shows also several other heavier elements .
The measured abundances agree only partly with the predictions of the radiative levitation theory .
We attribute this to current limitations of the models and the probable presence of mass loss .
In the spectrum of CD -38 ^ { \circ } 10980 , we have observed the quasi-molecular satellites of L \beta .
This confirms theoretical predictions about the visibility range for these features .