R. Bullen Newton — Miocene Shells from Egypt. 199 



often involves conflicting elements, the relative value of which is 

 a matter of uncertainty. 



The figures given in illustration of the above observations are proiile sections 

 drawn very roughly to true scale (two inches to a mile) . Where a section is drawn 

 longitudinally down a valley, it is not always taken along a straight line, but is made 

 to follow the more important bends of the valley. The horizontal line in each figure 

 represents the sea-level (O.D.). 



IV. — Notes on some Marine Miocene Shells feom Egypt. 



By E.. Bullen Newton, F.G.S. 



(PLATES VIII AND IX.) 



rilHE marine Miocene shells from Egypt referred to in this paper 



L form part of the collection of Egyptian fossils sent to the 



British Museum for determination by Captain H. G. Lyons, E.E., 



F.G.S. , Director-General of the Geological Survey of Egypt. 



Several writers have contributed lists of marine molluscan species 

 occurring in the different Miocene areas of Egypt — the Siwa Oasis, 

 the Pyramids, Jebel Geneffe, Chalouflf, and the coast of the Bitter 

 Lake — -among whom may be mentioned, A. B. Orlebar,^ Oscar Fi-aas,^ 

 Ch. Laurent,^ Gerhard Rohlfs,* L. Lartet,* and Mayer-Eymar,^ but 

 for the most complete treatise on this subject we are indebted to 

 Dr. Theodor Fuchs," whose principal investigations were published 

 in the Palceontograpliica for 1883. 



Dr. Fuchs' interesting comparisons between the marine Miocene 

 shells of Egypt and those of the Vienna Basin enabled him to 

 establish the fact that a large number of the species were common 

 to both areas : a result more particularly noticeable when comparing 

 the " Grunden Schichten " ( = Helvetian) forms with those of the 

 Siwa Oasis, although certain other species were regarded as 

 analogous to those found in the " Horner Schichten " ( = Oligocene — 

 Aquitanian stage) and " Steinabrunner Schichten " ( = Miocene — 

 Tortonian stage) of the same Basin. The present collection 

 appears to contain representatives of the three lower stages of tlie 

 Miocene system, no true characteristic Oligocene forms having been 

 determined, viz. : — 



! Tortonian. 

 Helvetian. 

 Burdigalian (=Langhian). 



^ " Some Observations on the Geology of the Egyptian Desert" : Journ. Bombay 

 Branch Eoy. Asiatic Soc, 1846, No. x, pp. 229-250 ; 14 plates of fossils. 



- " Aus dem Orient: Geologische Beobachtungen am Nil, auf der Sinai-Halbinsel, 

 undin Syrien," 1867, pp. 157-173. 



^ "Essai Geol. sur les terrains de I'lsthme Suez " : Annuaire Soc. anciens eleves 

 Ecoles, Arts, Metiers, 1870, p 230. 



* " Von Tripolis nach Alexandrien," 1871, vol. ii, pi. iv. 



^ "Essai Geol. Palestine, I'E'gypte, et 1' Arabic," pt. ii, Paleontologie : Biblioth. 

 Hautes E'tudes Sci. Nat., vol. vii (1873), No. 2, pp. 48, 73. 



« " Zur GeologieEgyptens" : Viert. Nat. Ges. Ziirich, vol. xxxi (1886), pp. 263-5. 



■^ " Die Geologische Beschaffenheit der Landenge von Suez " : Denk. Akad. Wiss. 

 "Wien., vol. xxxviii (1878), pt. 2, pp. 36-8. In ZittePs memoir, " Ueber den 

 Geologischen Ban der libyschen "Wiiste," 1880, pp. 41-5. " Beitrage Kenntniss 

 Miocaenfauna Aegyptens und der libyschen Wiiste" (in Zittel's work on Egypt) : 

 Palseontographica, vol. xxx (1883), pp. 19-66 (or pp. 1-48), pis. vi-xiii (i-viii) and 

 xix-xxii (xiv-xvii). 



