406 MAYER-EYMAR. — DIAGNOSHS D'HUITRES NOUVELLES 3o 



angusto, canali angusto, profundo, areas œquante, areis planis, trans- 

 versim rugatis; marginibus superne leviter scrobiculatis ; cicatricula 

 musculi magna, late semilunari, vix obliqua, margini postico appro- 

 ximata; valva superiore minore, plana, lamellosa. — Long. 73, 

 lat. 57 millim. 



Parisien supérieur (II, b) du Wadi el Tih (2) — Z. 



Groupe de YOstrea edulis. 

 Ostrea ramosa, May.-Eym. 



O. testa ovato-subtrigona, recta, leviter compressa, solidula ; valva 

 inferiorè dorso pro parte adnata, applanata; costis non multis, eleva- 

 tis, rotundatis, distantiusculis, sœpe dichotomis, inferioribus crassis, 

 latcralibus sensim minoribus, omnibus a lamellis incremenli irregula- 

 ribus sulcato-tegulatis; umbone sensim angustato, subacuto ; latere 

 inferiorè paulum arcuato, postico inferne angulato ; cardine angusto, 

 triangulari, canali angusto, profundo; marginibus superne leviter 

 scrobiculatis, inferne profunde dentatis ; valva superiore minore, 

 plana, eoncentrice lamellosa. — Long. 44, lat. 37 millim. 



Parisien inférieur (I, a) de Miniéh(i) — M, 



Ostrea ventilabrulum, May.-Eym. 



O. testa parva, ovato-rotundata vel subtriangulari, recta, compressa, 

 solidula ; valva inferiorè plano-convexa, umbone leviter adnata; costis 

 radiantibus non multis, depresso-fornicatis, divergentibus, plerumque 

 dichotomis, a lamellis incrementi plus minusve distantibussquamoso- 

 tegulatis, posticis minoribus ; umbone acutulo, leviter obliquo ; latere 

 antico longo, ratundato, postico in medio plus minusve concavo, 

 inferne anguloso ; cardine brevi, triangulari, canali latiusculo, areis 

 validiusculis; cicatricula musculi transversa, subovata ; valva supe- 

 riore minore, plana vel plano-convexa, lamellosa. — Long. 32, lat. 

 3o millim. 



Bartonien inférieur de la contrée Sud-Est de l'oasis de Siwah (4), — M. 

 Groupe de YOstrea multicostata. 

 Ostrea restans, May.-Eym. 



O. testa parva, ovata, subrecta ; valva inferiorè solidula, satis con- 

 vexa, umbone vel parte dorsi superiore adnata ; costis paucis, crassu- 

 lis, fornicatis, undatis, interdum dichotomis, a lamellis incrementi 

 leviter nodulosis, posticis minoribus; umbone parvo, acutiusculo; 

 cardine triangulari, modo recto, modo incurvo, canali angusto, profun- 

 diusculo, areis validulis; marginibus superne puncticulatis; cicatricula 

 musculi semicirculari", paulum obliqua ; valva superiore plana vel 



