PLATE XLII. 



PlKH.AIXl.MVA {ciiiilunietl). 



"Figs. 



1. P. decmmtn (Mant.). Chalk Marl, Chertsey. York Museum. Left valve. 



(P. 250.) 



2. /'. cordata, Tate. Upper Chalk (White Limestone, zone of Bdemnitdla 



mucronata), Tamlacht, co. Derry. Museum of Practical Geology, 

 No. 23G28. a, left valve; h, dorsal view ; c, anterior view. (P. 253.) 



Genus — Myopholas, BonvUle. 



3. ]\f. sp. cf. semicostata (Agassiz). Lower Greensand, Furze Hill, Faringdon. 



Sedgwick Museum. Internal cast, a, right valve; Ji, dorsal view. 

 (P. 253.) 



Genus — Goniomya, Aijassiz. 



4, 5. G. Archiaci (Pict. and Ren.) Lower Greensand (Crackers), Athcrfield. 

 Sedgwick Museum. Right valves. 4 h, dorsal view of 4 a. (P. 254.) 



G, 7. G. Mailleana (d'Orb.). Sedgwick Museum. 6, Base of Chalk Marl, Chard; 

 a, part of left valve ; b, dorsal view. 7, Upper Greensand, near 

 Maiden Bradley ; right valve. (P. 255.) 



