28 U.S. NATIONAL MUSEUM BULLETIN 275 



Plateau Province. The Coastal Plain Province includes the Mediter- 

 ranean littoral from the seaward margins of the coastal plain to the 

 coastal escarpment and northernmost edge of the hamadas of the 

 Saharan steppe. The Cyrenaican Plateau comprises the massif of the 

 Cyrenaican Plateau including the Gebel el Achdar. 



Owing to the mild climate of these coastal areas and the greater 

 amounts of rainfall and higher humidity, vegetative cover is denser 

 and more varied than in other parts of Libya. This is particularly 

 true of the Cyrenaican Plateau, which receives more rainfall than any 

 other region of Libya and has a flora differing strikingly from that of 

 the surrounding lowlands. 



The ecologic and climatic distinctness of the Mediterranean Faunal 

 Area is reflected in the greater number of kinds of rodents that occur 

 there. Of the 56 kinds of rodents that occur in Libya, 31 are found 

 in the Mediterranean Faunal Area — 55 percent of the total Libyan 

 rodent fauna. 



The following species of rodents are restricted to the Mediterranean 

 Faunal Area: Microtus mustersi; Gerbillus eatoni; Gerbillus henleyi; 

 Meriones libycus; Psammomys obesus; Spalax ehrenbergi; and Allactaga 

 tetrad actyla. 



The species Rattus rattus and Rattus norvegicus are also restricted 

 to the coastal areas of Libya, but because of their commensal nature 

 and tendency to be disseminated by man, they are not included in the 

 above list. Because of its doubtful validity, Gerbillus grobbeni, which 

 was described from specimens collected near Derna, has not been 

 included. 



Local differentiation of rodent populations in the Mediterranean 

 Faunal Area has resulted in the formation of 16 subspecies representing 

 11 species. The majority of these subspecies (12) are restricted to the 

 Coastal Plain Province and include Gerbillus aureus favillus ; Gerbillus 

 eatoni eatoni; Gerbillus eatoni inflatus; Gerbillus eatoni versicolor; 

 Gerbillus campestris wassifi; Gerbillus henleyi henleyi; Meriones caudatus 

 conjalonierii; Meriones libycus auratus; Meriones libycus azizi; Psam- 

 momys obesus obesus; Psammomys obesus tripolitanus ; and Jaculus 

 deserti favillus. 



The vole, Microtus mustersi, and the following subspecies occur in 

 both the Cyrenaican Plateau Province and the Coastal Plain Prov- 

 ince: Gerbillus campestris brunnescens; Sjmlax ehrenbergi aegyptiacus: 

 Eliomys quercinus cyrenaicus; and Jaculus orientalis orientalis. With 

 the exception of Jaculus orientalis orientalis, all are more abundant in 

 the Cyrenaican Plateau Province. The subspecies Gerbillus campestris 

 brunnescens and Spalax ehrenbergi aegyptiacus are the most typical 

 rodents of the Cyrenaican Plateau and are common in almost all 

 types of habitat and at all elevations. 



