204 H. Bullen Newton — Miocene Shells from Egypt. 



the European (Eussia, Poland, etc.) species in its elongate shape 

 and somewhat acute ligamental region, it differs in the absence 

 of true digitiform plications on the external surface of the lower 

 or convex valve, this feature being replaced by a series of closely- 

 set, radial, and laniellose costse, typical of 0. Bohlfsi from the 

 Tertiaries of Persia. The Persian shell, however, has a much 

 rounder outline and lacks any elongation of the dorsal margin. 



The upper valves are depressed, and bear numerous concentric, 

 sub-lamellose growth-lines ; in the present collection some of these 

 are covered in places externally with parasitic bryozoa belonging 

 to the genus Cellepora. 



Horizon. — Miocene (Tortonian). 



Distribution. — Egypt : Siwa Oasis (Rohlfs and Fuchs) ; Jebel 

 Geneffe, near Suez (Fuchs) ; island on the Lake of Birket-el- 

 Qarum (Mayer-Eymar) ; Camp 21. Coll. Geol. Surv. Egypt, 

 No. 627/ Box No. 27a,^ and No. 361, Box No. 66a. 



OSTEEA GINGENSIS, Schlotheim, sp. 



Ostreo-Pinnite, Knorr : Eecueil Monumens Catastrophes Petrifications, vol. ii (1768), 



pt 1, p. 119, pi. D. 

 Ostracites Gingensis, Schlotheim: Taschenbuch (Leonhard), vol. vii (1813), p. 72. 

 Ostrea crispata, Goldfuss : Petrefacta Germanise, vol. ii (1833), p. 15, pi. Ixxvii, 



figs. \a-f. 

 Ostrea Gingensis, Hoernes, " Foss. Moll. Tert.-Beck. Wien" : Abhandl. k. k. geol. 



Reichs., vol. iv (1870), p. 452, pis. Ixxvi-lxxx. 

 Ostrea? Gingensis, Sacco : Moll. Terz. Piemonte, etc., 1897, pt. xxiii, p. 10, pi. iii, 



fig. 29. 



Description. — Shell with rather narrow, elongate valves ; lower 

 valve convex, concentrically and irregulai'ly lamellose, longitudinally 

 plicated, umbonal area slightly curved, triangular, more or less 

 pointed and with a deep ligamental fossula ; upper valve depressed, 

 operculate, and ornamented with rugose, concentric, lamellar lines of 

 growth. 



Dimensions (of largest specimen). — Height, 120 mm.; length, 

 65 mm. 



Eemarks. — The Egyptian specimens of this species have very 

 worn exteriors, the longitudinal plications being almost obliterated. 

 Hoernes has given some excellent illustrations of the shell from 

 the Vienna Basin, his largest example measuring 355 by 180 

 millimetres. This author's work must also be consulted for 

 a fuller synonymy of the species than is here offered. 



Horizon. — Miocene (Tortonian). In the manuscript lists Captain 

 Lyons refers to these specimens as belonging to the Upper Miocene 

 of Mayer-Eymar. 



Distribution. — Vienna Basin ; South Germany (Swabia) ; Switzer- 

 land ; Bohemia ; North Italy, etc. Egypt : west of Jebel Zait, 

 western shore of the Gulf of Suez, Coll. Geol. Surv. Egypt, 

 No. 622, Box No. 16a. 



1 Localitv for these numbers is not recorded. 



