Résumé
North Africa is the most important centre of diversification for the skinks of the genus Chalcides. Morocco alone is inhabited by 16 species of which nine are endemic, while eight species are known from Algeria, none of them endemic. We add here to this diversity a taxon that was first collected by PAUL PALLARY in 1925, discussed by PELLEGRIN in 1926, and whose status has been debated by several authors since without reaching a satisfactory consensus. In 2003 and 2008, two specimens with the same habitus as PALLARY's specimen were found near Missour (Morocco) and near Djelfa (Algeria), respectively. A molecular analysis based on mitochondrial and nuclear genes shows that these two recent individuals belong to an undefined lineage that is sister to Chalcides montanus, and that we describe here as a new subspecies. It shares many morphological features with the nominate subspecies, but differs most prominently in its colour pattern of five black stripes in the first third of the dorsum, ocelli on the dorsum and on the flanks that disappear roughly in the first third or half of the body, and two broad light dorsolateral bands that disappear around midbody; its genetic divergence is estimated at 4.2% in cytochrome b sequence and 0.8% in a concatenated alignment of several nuclear loci. This new taxon is presently known from three specimens and two localities in the Hauts Plateaux of eastern Morocco and Algeria.