388 Mayer-Eymar, Diagnoses Ostrearum novarum 



gulares, fornicatae, irregulariter tegulato-tubiilosae, superne 

 minores, ad margines sensim dilatatae depressioresque ; 

 umbones breves, lati, trianguläres, ille valvae inferioris 

 prominens ; cardo huius valvae regulariter triangularis, 

 transversim rugatus ; canali profimdiusculo, leviter arcuato, 

 areis latis, planis ; cardo alterae valvae latiusculus, planus; 

 cicatriculae musculi oblongae, laterales ; margines ex tote 

 laeves. — Long. 125, lat. 55 mm. 



T n g r i a n u m II : Ste-Croix-du-Mont prope Burdi- 

 galam (3) Mus. Tur. et Univ. cathol. Paris. 



Dertonianum I, b: Stazzano prope Dertonam 

 (1—2) Mus. Tur. 



E Serie Ostreae Addolii. 



Ostrea asciiformis, May.-Eym. 



Testa oblonga, oblique subtransversa, arcuata, angus- 

 tiuscula, antice brevissima, rotundata ; postice praelonga ; 

 valva inferior umbone adnata, superne profunda, crassula, 

 inferne subgeniculata, leviter dilatata, compressa, tenuis, 

 subtruncata; costae non niultae, elevatae, fornicatae, 

 irreguläres, lamelloso-tegulatae, ad marginem inferiorem 

 late divaricantes ; costellae supero-posticae transversae ; 

 umbo paulum angustatus obtususque ; cardo brevis, latus, 

 canali lato, humili, areis planis ; cicatricula musculi magna, 

 oblonga, obliqua, cardini approximata ; margines ad cardi- 

 nem leviter scrobiculati ; (valva superior plana, lamellosa). 

 — Long. 80, lat. 52 mm. 



Helvetianum II, b: Salles prope Burdigalam (1) 

 Mus. Tur. 



E Serie Ostreae Barklayi. 



Ostrea BachmannI, May.-Eym, 



Testa oblonga, angusta, medio geniculata, subtenuis ; 



