Pentastomes were collected from the lizard, Mabuya homalocephala, in Kenya. These were identified as belonging to the Group II species complex of the genus Raillietiella, or those forms with the second pair of hooks blunt-tipped, and are considered as Raillietiella gehyrae Bovien, 1927. A detailed description of the external and internal morphology of the adults, eggs, and larvae is presented and the morphological characteristics of these specimens are compared with those in descriptions from other hosts and localities. The systematics of this and other species of Raillietiella are discussed in the light of current knowledge concerning pentastome taxonomy. Although there appears to be considerable metrical variation, all the species with a blunt-tipped second pair of hooks (Group II of Raillietiella species from lizards) are morphologically indistinguishable based on this and previous descriptions, and all are considered in the present study as a single species, R. gehyrae. Also, the biology and life history of this species are discussed.