46 U.S. NATIONAL MUSEUM BULLETIN 2 75 



climatic patterns shifted in relation to the colder, moister pluvial 

 and warmer, drier interpluvial stages of the Pleistocene. 



The most recent study of the effects of the Pleistocene in Libya 

 is that of McBurney and Hey (1955), entitled "Prehistory and Pleisto- 

 cene Geology in Cyrenaican Libya." They consider the terraces on the 

 northern side of the Gebel Achdar of extreme northern Cyrenaica to 

 represent "ancient wave-cut platforms," and the cliffs to be also of 

 marine origin. They therefore recognize six (or possibly seven) differ- 

 ent shorelines corresponding to the number of terraces and the nature 

 of their deposits. They propose two deductions (p. 68) regarding the 

 manner of formation of these ancient shorelines. The first of these 

 postulates involves a series of "successively lower altitudes at which 

 sea-level halted, for a considerable length of time in each case, before 

 reaching its present position." These altitudes are estimated by 

 McBurney and Hey (p. 68) to consist of successive levels at: 140-200 

 meters (possibly representing two separate stages), 79-90, 44-55, 

 35-40, 15-25, and 6 meters. The second postulate considers the period 

 in which these terraces were formed to have been one of "almost com- 

 plete tectonic stability." 



This evidence from northern Cyrenaica indicates that sea-level 

 fluctuations from the highest level in Pliocene times to the lowest 

 6-meter level were punctuated by a series of intermediate shorelines 

 probably corresponding to the pluvial and interpluvial climatic changes 

 of the Pleistocene. McBurney and Hey conclude (p. 137) that during 

 the Pleistocene the climate of the Gebel Achdar "was influenced 

 profoundly," especially during the last continental glaciation (Wiirm 

 glaciation). 



In addition to establishing the pattern and sequence of ancient 

 shorelines in Cyrenaica, McBurney and Hey (1955) conducted ex- 

 tensive diggings in the Wadi Derna and in two caves in northern 

 Cyrenaica. The fossil mammals unearthed as a result of these investi- 

 gations were reported by Bate as an appendix to the archeological 

 text by McBurney and Hey (1955). These fossil mammals are largely 

 represented by fragments, but 15 species have been identified, most 

 of which shed interesting light on the Pleistocene mammalian fauna 

 of northern Cyrenaica and North Africa. 



Of particular interest to zoogeographical considerations in Libj'a 

 was the discovery in northern Cyrenaica of fossils of the field mouse, 

 Apodemus Kaup; the dormouse, Eliomys; a gerbil Gerbillus, and a vole. 

 Microtus. All except Apodemus occur in Cyrenaica today, and these 

 fossils probably represent earlier Pleistocene forms of the species 

 occurring today in Cyrenaica. The field mouse, Apodemus, is now 

 restricted in Africa to Algeria and northern Morocco. 



The remains of the fossil Cyrenaican vole were described as a new 

 species, Microtus cyrenae, by Bate (in McBurney and Hey, 1955, 



