  We present an elemental abundance analysis for four newly discovered ultra
metal-poor stars from the Hamburg/ESO survey, with $\mathrm{[Fe/H]}\leq-4$.
Based on high-resolution, high signal-to-noise spectra, we derive abundances
for 17 elements in the range from Li to Ba. Three of the four stars exhibit
moderate to large over-abundances of carbon, but have no enhancements in their
neutron-capture elements. The most metal-poor star in the sample,
HE~0233$-$0343 ($\mathrm{[Fe/H]} = -4.68$), is a subgiant with a carbon
enhancement of $\mathrm{[C/Fe]}= +3.5$, slightly above the carbon-enhancement
plateau suggested by Spite et al. No carbon is detected in the spectrum of the
fourth star, but the quality of its spectrum only allows for the determination
of an upper limit on the carbon abundance ratio of $\mathrm{[C/Fe]} < +1.7$. We
detect lithium in the spectra of two of the carbon-enhanced stars, including
HE~0233$-$0343. Both stars with Li detections are Li-depleted, with respect to
the Li plateau for metal-poor dwarfs found by Spite \& Spite. This suggests
that whatever site(s) produced C either do not completely destroy lithium, or
that Li has been astrated by early-generation stars and mixed with primordial
Li in the gas that formed the stars observed at present. The derived abundances
for the $\alpha$-elements and iron-peak elements of the four stars are similar
to those found in previous large samples of extremely and ultra metal-poor
stars. Finally, a large spread is found in the abundances of Sr and Ba for
these stars, possibly influenced by enrichment from fast rotating stars in the
early universe.
