A report on 45 lizards and snakes, representing 23 species and subspecies, collected in northern and southwestern Transjordan, mostly during 1963-1965. Taxonomic characters are presented, and compared with data from adjacent areas, mainly Cisjordan. Relevant Transjordanian specimens in the Hebrew University of Jerusalem are also considered, and some identifications are revised. Field observations are cited. Agama pallida haasi ssp. nov. is described (type: BM 1965.800; 18 paratypes in BM, HUJ, FMNH). The only additions, on the species level, to the Transjordanian fauna, are Coluber rhodorhachis Jan and Malpolon moilensis Reuss. The ecological and phytogeographical subdivision of Transjordan into Mediterranean, Irano-Turanian, and Saharo-Sindian territories is reviewed. The distribution of reptiles appears to accord with this subdivision. The difference between the herpetofaunas of Trans- and Cisjordan, on the specific and subspecific levels, is greater in the south than in the north. Notably 7 Irano-Turanian and Saharo-Sindian forms of Transjordan do not occur in Cisjordan. It is suggested that the Wadi 'Arava together with the steep mountains bordering it on the east, may constitute a barrier to the distribution of reptiles.