534 R. Biillen Newton — Egyptian Loiver Tertiary Shells. 



Horizon. — Oligocene ? 



Distribution. — Egypt : Wadi Natrum. Coll. Geol. Surv. Egypt 

 (No. 635 ; Box Nos. Ma, 4:5a, 4Q,a). 



CONUS and VOLUTA. 



Eemakks, — The collection contains some worn and fragmentary 

 specimens of Conns and Voluta, which are unfortunately not 

 specifically determinable ; they occur in a light foraminiferal lime- 

 stone associated with Mitra turricnlata and Hippochreues, sp. 



Horizon. — Middle Eocene (Mokattam Series). 



Distribution. — Egypt: Minyeh. Coll. Geol. Surv. Egypt (No. 

 8M, Box No. 12c). 



[Gasteropod Casts — indeterminable.] 

 Remarks. — Two fragments of a light-coloured matrix containing 



casts of a small univalve shell without definition. 

 Horizon. — Eocene (?). 

 Distribution. — Egypt : Wadi Natrum. Coll. Geol. Surv. Egypt 



(No. 638, Box No. 49a). 



Gasteropods and Lamellibranchs — indeterminable. 



Eemarks. — A number of diminutive moHusca belonging to the 

 genera Fotamaclis, Corhula, etc., mostly casts and impressions, are 

 contained in a fawn-coloured calcareous sandstone, which is made 

 up of innumerable rounded fragments of quartz, agglutinated by 

 a siliceous cement. Professor Mayer-Eymar^ has described a some- 

 what similar sandstone from the neighbourhood of Cairo, in which 

 he has recognized eighteen species of shells under the genera Astarte, 

 Cyrena, Tellina, Corhula, Hydrobia, Melanopsis, Fotamaclis, etc., 

 regarding them as of Tongrian age. 



Horizon. — Oligocene ? 



Distribution. — Egypt : Wadi Faregh, south-east of Wadi Natrum. 

 Coll. Geol. Surv. Egypt (No. 634, Box Nos. 38a to 43a). 



MOLLTJSCA: LAMELLIBEANCHIATA. 



Genus OSTREA, Linnaeus. 

 Systema Naturee, 1758, ed. x, p. 696. 

 Type. — 0. edulis, Linngeus. 



Ostrea aviola, Mayer-Eymar. (PI. XIX, Figs. 5-8.) 



Ostrea aviola, Mayer-Eymar, " Diagnoses Ostrearum novarum ex 



agris JEgyptige": Viert. Nat. Ges. Zurich, vol. xxxiv (1889), 



p. 297 (not figured). 



Description. — 0. testa parva, satis variabili, modo ovata, modo 



ovato-rotundata, modo subquadrata, leviter obliqua, modo tenuiuscula, 



1 "Zur Geologie Egyptens": Vierfc. Nat. Ges. Zurich, vol. xxxi (1886), p. 261. 

 " Ueber das Tongrian von Cairo (Egypten) " : ibid., vol. xxxiv (1889), p. 195 and 

 plate of fossils. ' ' Le Ligurien et le Tongrien en Egypte ' ' : Bull. See. Geol. France, 

 ser. Ill, vol. xsi (1893), p. 31. 



