In 450 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of Ds−ℓ+ and Λc+ℓ− combinations have been measured. 16.0 ± 4.3 Ds−ℓ+ combinations were observed in the Ds− → ππ− channel and 17.0 ± 4.5 combinations were observed in the channel. 21.0 ± 5.0 Λc+ℓ− combinations were observed, with the Λc+ reconstructed in the decay mode Λc+ → pK−π+. These events provide evidence for the decays . Assuming that the Bs and Λb semileptonic decays are dominantly three-body, these observed yields, after background subtraction, translate into the following product branching ratios: , .