370 F. Chapman — Tertiary Foraminifera 



The group of Nummulites Gizehensis (Fovskal), Ehrenberg, 

 From a zoological standpoint the various forms of nummulites so 

 closely associated in certain beds of the Mokattam Series in Egypt 

 and neighbouring areas, referred to under the name of N. Gizehensis 

 and its varieties, are clearly local modifications of the more widely 

 distributed Nummulites complanata, Lamarck. In consideration of 

 the practical use of distinctive terms for local varieties in relation to 

 their stratigraphical distribution, it is here proposed to retain the 

 grouping of this series so minutely and carefully worked out by 

 Dr. De la Harpe. 



Nummulites Gizehensis (Forskal), Ehrenberg, var. Ehrenhergi, 



De la Harpe. (PI. XIV, Fig. 15.) 



Nautilus Oyzehensis, Forskal, 1775 : Descriptiones Animalium, p. 140. 1776 : 



Icones rerum naturalium, etc. 

 Nummulites Gyzehensis, Ehrenberg, 1838 : Abhandl. Akad. "Wiss. Berlin, p. 93. 

 N. Gyzehe7isis, Ehr., d'Archiac & Haime, 1853 : Descr. Anim. groupe nummulitique 



Inde, vol. i, p. 94, pi. ii, figs. 6a-/, 7«, 8. 

 N. Gizehensis Ehrenhergi, De la Harpe, 1883 : Palseontograpliica, vol. sxx, Pal. 

 Theil, p. 190, pi. xxxii, figs. 16-25 ; pi. xxxiii, figs. 1, 2. 



This is the well-known form with the thick disc and rounded 

 edge. The septa between each chamber are unusually thick and 

 inclined. 



This variety has been chiefly obtained from Egypt, but it has also 

 been recorded from Sinai, Syria, Anatolia, and Vicentin. In Sinai it 

 occurred at Wady Gharandel (Eupert Jones and Bauerman). It has 

 also been doubtfully recorded from Biarritz. 



Coll. Geol. Surv. Egypt, No. 4,163, Box No. 51. Mokattam Series 

 (Middle Eocene) : near top of Jebel Safariat, Sinai. Several 

 specimens. 

 Nummulites Gizehensis (Forskal), Ehrenberg, var. Lyelli, d'Archiac & 



Haime. (PI. XIV, Fig. 14.) 

 Nummulites Lyelli (pars), d'Archiac & Haime, 1853 : Descr. Anim. groupe nummu- 

 litique Inde, vol. i, p. 95, pi. iii, figs, la, b, 2. Fraas, 1867 : Aus dem 

 Orient, p. 129. 

 N. Gizehensis Lyelli, d'Archiac, De la Harpe, 1883 : Paleeontographica, vol. xxx, 

 Pal. Theil, p. 192, pi. xxxiii (iv), figs. 3-10. 



This is a large variety, and perhaps approaches the type N. com- 

 planata most closely. It is rather regular in outward form, and has 

 the peripheral edge fairly sharp and thin. The septa, seen in 

 section, run nearly straight across from whorl to whorl, especially 

 in the later turns of the shell, instead of being arcuate and inclined, 

 as in the variety previously mentioned. The chambers are irregularly 

 spaced. The specimens from Sinai measure as much as 38 mm. in 

 diameter and about 6 mm. in thickness. 



N. Gizehensis, var. Lyelli, has been recorded from Egypt, near 

 Cairo ; and from Syria, in the white limestone of Gerizhem. 



Coll. Geol. Surv. Egypt, No. 4,163, Box No. 51. Mokattam Series 



(Middle Eocene) : near top of Jebel Safariat, Sinai. Very common. 



Nummulites Gizehensis (Forskal), Ehrenberg, var. Pachoi, De la Harpe. 



Nummulites Gizehensis Pachoi, De la Harpe, 1883: Palseontographica, vol. xxx, 



Pal. Theil, p. 193, pi. :£xxiii (iv), figs. 14-18; pi. xxxiv (v), figs. 1-5. 



