  We present the study of $\bar{B}^{0} \to \Sigma_{c}(2455)^{0,++} \pi^{\pm}
\bar{p}$ decays based on $772\times 10^{6}$ $B\bar{B}$ events collected with
the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The
$\Sigma_{c}(2455)^{0,++} $ candidates are reconstructed via their decay to
$\Lambda_{c}^{+} \pi^{\mp}$ and $\Lambda_{c}^{+}$ decays to
$pK^{-}\pi^{+},~pK_{S}^{0},$ and $\Lambda\pi^{+}$ final states. The
corresponding branching fractions are measured to be ${\cal B}(\bar{B}^{0} \to
\Sigma_{c}(2455)^{0} \pi^{+} \bar{p}) = (1.09 \pm 0.06 \pm 0.07)\times10^{-4}$
and ${\cal B}(\bar{B}^{0} \to \Sigma_{c}(2455)^{++} \pi^{-} \bar{p}) = (1.84\pm
0.11 \pm 0.12)\times 10^{-4}$, which are consistent with the world average
values with improved precision. A new structure is found in the
$M_{\Sigma_{c}(2455)^{0,++}\pi^{\pm}}$ spectrum with a significance of
$4.2\sigma$ including systematic uncertainty. The structure is possibly an
excited $\Lambda_{c}^{+}$ and is tentatively named $\Lambda_{c}(2910)^{+}$. Its
mass and width are measured to be $(2913.8 \pm 5.6 \pm 3.8)$ MeV/$c^{2}$ and
$(51.8\pm20.0 \pm 18.8)$ MeV, respectively. The products of branching fractions
for the $\Lambda_{c}(2910)^{+}$ are measured to be ${\cal B}(\bar{B}^{0} \to
\Lambda_{c}(2910)^{+}\bar{p})\times{\cal B}(\Lambda_{c}(2910)^{+} \to
\Sigma_{c}(2455)^{0}\pi^{+}) = (9.5 \pm 3.6 \pm 1.6)\times 10^{-6}$ and ${\cal
B}(\bar{B}^{0} \to \Lambda_{c} (2910)^{+}\bar{p})\times {\cal
B}(\Lambda_{c}(2910)^{+} \to \Sigma_{c}(2455)^{++}\pi^{-}) = (1.24 \pm 0.35 \pm
0.10)\times 10^{-5}$. Here, the first and second uncertainties are statistical
and systematic, respectively.
