We report measurements of the branching fractions of the decays $\Lambda_c^+\to\Sigma^+\pi^-\pi^+$, $\Lambda_c^+\to\Sigma^0\pi^+\pi^0$ and $\Lambda_c^+\to\Sigma^+\pi^0\pi^0$ relative to the reference channel $\Lambda_c^+\to pK^-\pi^+$. The charmed-strange baryon $\Xi_c(2930)^0$, decaying to $K^-\Lambda_c^+$, is observed for the first time in $B^-\to K^-\Lambda_c^+\bar{\Lambda}_c^-$ decays. We also measure ${\cal B}(B^-\to K^-\Lambda_c^+\bar{\Lambda}_c^-)$ with improved precision, and search for the charmonium-like state $Y(4660)$ and its spin partner, $Y_{\eta}$, in the $\Lambda_c^+\bar{\Lambda}_c^-$ invariant mass spectrum. Decays of the $\Omega_c^0$ charmed baryon into hadronic final states were studied. We present the results of a study of excited $\Omega_c$ charmed baryons in the decay mode $\Xi_c^+K^-$.