Whilst engaged in revising the Aethiopian species of Cerceris Latreille, 1802, the author had pleasure in identifying a small collection belonging to the Rijksmuseum van Natuurlijke Historie, Leiden, kindly submitted to him by Dr. M. A. Lieftinck. This collection comprised specimens collected in Aethiopian territories, North Africa and Corsica, the North African and Corsican species having been personally collected by Dr. Lieftinck. A subsequent study of the Corsican material led to the discovery of an apparent new subspecies of Cerceris sabulosa (Panzer, 1799) (Philanthinae, tribe Cercerini) and it is fitting that Dr. Lieftinck is honoured here with this subspecific discovery. Cerceris sabulosa lieftincki subspec. nov. Female: 11 mm long. In coloration very much the same as that of the nominal subspecies, Cerceris sabulosa sabulosa (Panzer, 1799); except that the fourth tergite is completely black and the yellow markings on the sternites are confined to very small lateral maculae on the second and large lateral areas of the third sternite, similar to that of Cerceris sabulosa algerica (Thunberg, 1815). The flagellum is blackish with faint traces of dark ferruginous on the underside. The propodeum is without lateral yellow maculae. Structurally, especially the clypeal and pygidial shapes and proportions, C.s. lieftincki is the same as the nominal subspecies, but there is a marked difference in the puncturation, sufficient to separate C.s. lieftincki subspecifically from Cerceris s. sabulosa (Panzer), and Cerceris sabulosa algerica (Thunberg). The differences lie in the formation of the punctures on the tergites, as follows: the punctures on the second tergite follow the same reticulate pattern of C.s. sabulosa, but are distinctly larger and placed slightly