DES TERRAINS NUMMULITIQUES D'ÉGYPTE 40 3 



crassula, i.rregulari, dorso pro parte affixa, irregulariter crassilamellosa : 

 costis non multis, irregularibus, depressis, plerumque obscuris, pro 

 parte a lamellis leviter crispatis; umbone prominente, obtusulo; car- 

 dine leviter obliquo, triangulari ; canali areas aequante, areis validis, 

 planis ; marginibus superne tenue scrobiculatis ; cicatricula musculi 

 majuscula, semicirculari ; valva superiore plana, multilamellosa, obs- 

 cure radiata; cardine lato, piano; marginibus superne crenulatis. — 

 Long. 62, lat. 48 millim. 



Parisien inférieur (I,a?) de Nokba (Oasis deParafrah) (2) — M. 



Groupe de YOstrea Polyphemus. 

 Ostrea fluctuosa, May.-Eym. 



O. testa angusta, leviter arcuata; valva inferiore crassissima, dorso 

 obtuse carinata, gibbosa ; costis novenis, ad umbonem ninatissimis, 

 dorso subevanescentibus, inferne valde inaequalibus, alternantibus, 

 majoribus crassissimis, a lamellis concentricis crassis, fluctuosis, irre- 

 gularibus, squamoso-spinosis ; umbono longo, angusto, obliquo ; 

 cardine angusto, canali longiusculo, profundo, areis angustissimis ; 

 marginibis superne leviter scrobiculatis ; inferne undatis; cicatricula 

 musculi obtuse triangulari ; valva superiore minore, plana, lamellosa. 

 — Long. 48, lat. 28 millim. 



Londinien inférieur de Nokba (Oasis de Farafrah (1) — M. 



Ostrea Livingstoni, May.-Eym. 



O. testa maxima, ovato-oblonga, recta, compressa, incrassata ; 

 valva inferiore crassissima, ad umbonem leviter angustata; lamellis 

 concentricis crassis, irregularibus, distantibus, plus minusve reflexis, 

 a costulis radiantibus numerosis, depressis, ssepe obscuris, subcris- 

 patis; cardine longiusculo, triangulari, canali lato, parum profundo, 

 areis angustis, rugosis ; marginibus pro parte maxima leviter scrobicu- 

 latis ; cicatricula musculi semicirculari, mediana, margini inferiori 

 viciniore quam cardini ; valva superiore plano-convexa, lamellis 

 concentricis crassis, irregularibus ; umbone angusto ; canali triangu- 

 lari, subpiano ; marginibus superne scrobiculato-crenatis. — Long. 

 145, lat. 76 millim. 



Parisien supérieur (II, e) : Wadi el Tih (3) — Z. 



Ostrea Qemniana, May.-Eym. 



O. testa ovato-oblonga, extremitatibus angustata, fere recta, cras- 

 sula, compressa, submargaritacea ; valva infbriori irregulariter tenui- 

 lamellosa, concentrice tenuisulcata, radiatim obscure pauicostata ; 

 umbone acutiusculo ; cardine elongato, recto, transversim striato- 



