The series is, therefore, 

 a steadily ascending one 

 from Mersa Susa to Cyrene. 



The old port of Mersa 

 Susa is built on a series of 

 dune - limestones, behind 

 which is an alluvial delta 

 deposited 03- the Wadi Susa. 

 The route to Cyrene goes 

 westwards across the allu- 

 vial deposits for about a 

 mile ; and then, in the 

 banks of a large wadi, 

 limestone is exposed dipping 

 5° northwards and contain- 

 ing Gisortia gigantea Munst., 

 Tr achy car dium cf. granco- 

 nense Oppenh., and Pecten 

 arcuatus Brocchi. Mr. New- 

 ton, therefore, refers this 

 limestone to thePriabonian. 1 

 At the foot of the plateau 

 the cherty limestones — the 

 Apollonia Limestones — are 

 exposed, and they continue 

 up the track from 150 to 

 530 feet above sea-level. 

 This limestone, as a rule, is 

 massive, and contains many 

 foraminifera and some shell- 

 fragments. Some indeter- 

 minable molluscs were col- 

 lected at the height of 450 

 feet in a band of cherty 

 limestone. The chert-bearing 

 series ends at the height of 

 530 feet with a chert-breccia. 

 Above this follows the 

 compact, creamy - white 

 Derna Limestone, full of 

 Nummulites curuispira and 

 identical in character with 

 that so well exposed at 

 Derna. At 600 feet is a 

 white, foraminiferal lime- 

 stone with echinoid frag- 

 ments. At 620 feet is an 

 oolitic band, also observed at 

 a corresponding position in 

 the section above Ptolemeta. 



1 The specimen determined as Nummulites perforata by the late Prof. T. 

 Rupert Jones from Mersa Susa doubtless came from the same limestone, with 

 which it agrees lithologically. Mr. Newton has kindly examined it, and is 

 disposed to regard it as N. intermedia, an Upper^Eocene species. 



